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Bryan Cardella

Bryan Cardella

DNA

Slide Duration:

Table of Contents

I. Introduction to Biology
Scientific Method

26m 23s

Intro
0:00
Origins of the Scientific Method
0:04
Steps of the Scientific Method
3:08
Observe
3:21
Ask a Question
4:00
State a Hypothesis
4:08
Obtain Data (Experiment)
4:25
Interpret Data (Result)
5:01
Analysis (Form Conclusions)
5:38
Scientific Method in Action
6:16
Control vs. Experimental Groups
7:24
Independent vs. Dependent Variables
9:51
Other Factors Remain Constant
11:03
Scientific Method Example
13:58
Scientific Method Illustration
17:35
More on the Scientific Method
22:16
Experiments Need to Duplicate
24:07
Peer Review
24:46
New Discoveries
25:23
Molecular Basis of Biology

46m 22s

Intro
0:00
Building Blocks of Matter
0:06
Matter
0:32
Mass
1:10
Atom
1:48
Ions
5:50
Bonds
8:29
Molecules
9:55
Ionic Bonds
9:57
Covalent Bonds
11:10
Water
12:30
Organic Compounds
17:48
Carbohydrates
18:04
Lipids
19:43
Proteins
20:42
Nucleic Acids
22:21
Carbohydrates
22:54
Sugars
22:56
Functions
23:42
Molecular Representation Formula
26:34
Examples
27:15
Lipids
28:44
Fats
28:46
Triglycerides
29:04
Functions
32:10
Steroids
33:43
Saturated Fats
34:18
Unsaturated Fats
36:08
Proteins
37:26
Amino Acids
37:58
3D Structure Relates to Their Function
38:54
Structural Proteins vs Globular Proteins
39:41
Functions
40:41
Nucleic Acids
42:53
Nucleotides
43:04
DNA and RNA
44:34
Functions
45:07
II. Cells: Structure & Function
Cells: Parts & Characteristics

1h 12m 12s

Intro
0:00
Microscopes
0:06
Anton Van Leeuwenhoek
0:58
Robert Hooke
1:36
Matthias Schleiden
2:52
Theodor Schwann
3:19
Electron Microscopes
4:16
SEM and TEM
4:54
The Cell Theory
5:21
3 Tenets
5:24
All Organisms Are Composed of One Or More Cells
5:46
The Cell is the Basic Unit of Structure and Function for Organisms
6:01
All Cells Comes from Preexisting Cells
6:34
The Characteristics of Life
8:09
Display Organization
8:18
Grow and Develop
9:12
Reproduce
9:33
Respond to Stimuli
9:55
Maintain Homeostasis
10:23
Can Evolve
11:37
Prokaryote vs. Eukaryote
11:53
Prokaryote
12:13
Eukaryote
14:00
Cell Parts
16:53
Plasma Membrane
18:27
Cell Membrane
18:29
Protective and Regulatory
18:52
Semi-Permeable
19:18
Polar Heads with Non-Polar Tails
20:52
Proteins are Imbedded in the Layer
22:46
Nucleus
25:53
Contains the DNA in Nuclear Envelope
26:31
Brain on the Cell
28:12
Nucleolus
28:26
Ribosome
29:02
Protein Synthesis Sites
29:25
Made of RNA and Protein
29:29
Found in Cytoplasm
30:24
Endoplasmic Reticulum
31:49
Adjacent to Nucleus
32:07
Site of Numerous Chemical Reactions
32:37
Rough
32:56
Smooth
33:48
Golgi Apparatus
34:54
Flattened Membranous Sacs
35:10
Function
35:45
Cell Parts Review
37:06
Mitochondrion
39:45
Mitochondria
39:50
Membrane-Bound Organelles
40:07
Outer Double Membrane
40:57
Produces Energy-Storing Molecules
41:46
Chloroplast
43:45
In Plant Cells
43:47
Membrane-Bound Organelles with Their Own DNA and Ribosomes
44:20
Thylakoids
44:59
Produces Sugars Through Photosynthesis
45:46
Vacuoles/ Vesicles
46:44
Vacuoles
47:03
Vesicles
47:59
Lysosome
50:21
Membranous Sac for Breakdown of Molecules
50:34
Contains Digestive Enzymes
51:55
Centrioles
53:15
Found in Pairs
53:18
Made of Cylindrical Ring of Microtubules
53:22
Contained Within Centrosomes
53:51
Functions as Anchors for Spindle Apparatus in Cell Division
54:06
Spindle Apparatus
55:27
Cytoskeleton
55:55
Forms Framework or Scaffolding for Cell
56:05
Provides Network of Protein Fibers for Travel
56:24
Made of Microtubules, Microfilaments, and Intermediate Filaments
57:18
Cilia
59:21
Cilium
59:27
Made of Ring of Microtubules
1:00:00
How They Move
1:00:35
Flagellum
1:02:42
Flagella
1:02:51
Long, Tail-Like Projection from a Cell
1:02:59
How They Move
1:03:27
Cell Wall
1:05:21
Outside of Plasma Membrane
1:05:25
Extra Protection and Rigidity for a Cell
1:05:52
In Plants
1:07:19
In Bacteria
1:07:25
In Fungi
1:07:41
Cytoplasm
1:08:07
Fluid-Filled Region of a Cell
1:08:24
Sight for Majority of the Cellular Reactions
1:08:47
Cytosol
1:09:29
Animal Cell vs. Plant Cell
1:09:10
Cellular Transport

32m 1s

Intro
0:00
Passive Transport
0:05
Movement of Substances in Nature Without the Input of Energy
0:14
High Concentration to Low Concentration
0:36
Opposite of Active Transport
1:41
No Net Movement
3:20
Diffusion
3:55
Definition of Diffusion
3:58
Examples
4:07
Facilitated Diffusion
7:32
Definition of Facilitated Diffusion
7:49
Osmosis
9:34
Definition of Osmosis
9:42
Examples
10:50
Concentration Gradient
15:55
Definition of Concentration Gradient
16:01
Relative Concentrations
17:32
Hypertonic Solution
17:48
Hypotonic Solution
20:07
Isotonic Solution
21:27
Active Transport
22:49
Movement of Molecules Across a Membrane with the Use Energy
22:51
Example
23:30
Endocytosis
25:53
Wrapping Around of Part of the Plasma
26:13
Examples
26:26
Phagocytosis
28:54
Pinocytosis
29:02
Exocytosis
29:40
Releasing Material From Inside of a Cell
29:43
Opposite of Endocytosis
29:50
Cellular Energy, Part I

52m 11s

Intro
0:00
Energy Facts
0:05
Law of Thermodynamics
0:16
Potential Energy
2:27
Kinetic Energy
2:50
Chemical Energy
3:01
Mechanical Energy
3:20
Solar Energy
3:41
ATP Structure
4:07
Adenosine Triphosphate
4:12
Common Energy Source
4:25
ATP Function
6:13
How It Works
7:18
What It Is Used For
7:43
GTP
9:36
ATP Cycle
10:35
ATP Formation
10:49
ATP Use
12:12
Enzyme Basics
13:51
Catalysts
13:59
Protein-Based
14:39
Reaction Occurs
14:51
Enzyme Structure
19:14
Active Site
19:23
Induced Fit
20:15
Enzyme Function
21:22
What Enzymes Help With
21:31
Inhibition
21:57
Ideal Environment to Function Properly
22:57
Enzyme Examples
25:26
Amylase
25:34
Catalase
26:03
DNA Polymerase
26:21
Rubisco
27:06
Photosynthesis
28:19
Process To Make Glucose
28:27
Photoauthotrophs
28:34
Endergonic
30:08
Reaction
30:22
Chloroplast Structure
31:55
Photosynthesis Factories Found in Plant Cells
32:26
Thylakoids
32:29
Stroma
33:18
Chloroplast Micrograph
34:14
Photosystems
34:46
Thylakoid Membranes Are Filled with These Reaction Centers
34:58
Photosystem II and Photosystem I
35:47
Light Reactions
37:09
Light-Dependent Reactions
37:24
Step 1
37:35
Step 2
38:31
Step 3
39:33
Step 4
40:33
Step 5
40:51
Step 6
41:30
Dark Reactions
43:15
Light-Independent Reactions or Calvin Cycle
43:19
Calvin Cycle
44:54
Cellular Energy, Part II

40m 50s

Intro
0:00
Aerobic Respiration
0:05
Process of Breaking Down Carbohydrates to Make ATP
0:45
Glycolysis
1:44
Krebs Cycle
1:48
Oxidative Phosphorylation
2:06
Produces About 36 ATP
2:24
Glycolysis
3:35
Breakdown of Sugar Into Pyruvates
4:16
Occurs in the Cytoplasm
4:30
Krebs Cycle
11:40
Citric Acid Cycle
11:42
Acetyl-CoA
12:04
How Pyruvate Gets Modified into acetyl-CoA
12:35
Oxidative Phosphorylation
22:45
Anaerobic Respiration
29:44
Lactic Acid Fermentation
31:06
Alcohol Fermentation
31:51
Produces Only the ATP From Glycolysis
32:09
Aerobic Respiration vs. Photosynthesis
36:43
Cell Division

1h 9m 12s

Intro
0:00
Purposes of Cell Division
0:05
Growth and Development
0:17
Tissue Regeneration
0:51
Reproduction
1:51
Cell Size Limitations
4:01
Surface-to-Volume Ratio
5:33
Genome-to-Volume Ratio
10:29
The Cell Cycle
12:20
Interphase
13:23
Mitosis
14:08
Cytokinesis
14:21
Chromosome Structure
16:08
Sister Chromatids
19:00
Centromere
19:22
Chromatin
19:48
Interphase
21:38
Growth Phase #1
22:25
Synthesis of DNA
23:09
Growth Phase #2
23:52
Mitosis
25:13
4 Main Phases
25:21
Purpose of Mitosis
26:40
Prophase
28:46
Condense DNA
28:56
Nuclear Envelope Breaks Down
29:44
Nucleolus Disappears
30:04
Centriole Pairs Move to Poles
30:31
Spindle Apparatus Forms
31:22
Metaphase
32:36
Chromosomes Line Up Along Equator
32:43
Metaphase Plate
33:29
Anaphase
34:21
Sister Chromatids are Separated
34:26
Sister Chromatids Migrate Towards Poles
36:59
Telophase
37:17
Chromatids Become De-Condensed
37:31
Nuclear Envelope Reforms
37:59
Nucleoli Reappears
38:22
Spindle Apparatus Breaks Down
38:32
Cytokinesis
39:01
In Animal Cells
39:31
In Plant Cells
40:38
Cancer in Relation to Mitosis
41:59
Cancer Can Occur in Multicellular Organism
42:31
Particular Genes Control the Pace
43:11
Benign vs. Malignant
45:13
Metastasis
46:45
Natural Killer Cells
47:33
Meiosis
48:17
Produces 4 Cells with Half the Number of Chromosomes
49:02
Produces Genetically Unique Daughter Cells
51:56
Meiosis I
52:39
Prophase I
53:14
Metaphase I
57:44
Anaphase I
59:10
Telophase I
1:00:00
Meiosis II
1:01:04
Prophase II
1:01:08
Metaphase II
1:01:32
Anaphase II
1:02:08
Telophase II
1:02:43
Meiosis Overview
1:03:39
Products of Meiosis
1:06:00
Gametes
1:06:10
Sperm and Egg
1:06:17
Different Process for Spermatogenesis vs. Oogenesis
1:06:27
III. From DNA to Protein
DNA

51m 42s

Intro
0:00
DNA: Its Role and Characteristics
0:05
Deoxyribonucleic Acid
0:17
Double Helix
1:28
Nucleotides
2:31
Anti-parallel
2:46
Self-Replicating
3:36
Codons, Genes, Chromosomes
3:56
DNA: The Discovery
5:13
DNA First Mentioned
5:50
Bacterial Transformation with DNA
6:32
Base Pairing Rule
8:06
DNA is Hereditary Material
9:44
X-Ray Crystallography Images
10:46
DNA Structure
11:49
Nucleotides
12:54
The Double Helix
16:34
Hydrogen Bonding
16:40
Backbone of Phosphates and Sugars
19:25
Strands are Anti-Parallel
19:37
Nitrogenous Bases
20:52
Purines
21:38
Pyrimidines
22:46
DNA Replication Overview
24:33
DNA Must Duplicate Every Time a Cell is Going to Divide
24:34
Semiconservative Replication
24:49
How Does it Occur?
27:34
DNA Replication Steps
28:39
DNA Helicase Unzips Double Stranded DNA
28:49
RNA Primer is Laid Down
29:10
DNA Polymerase Attaches Complementary Bases in Continuous Manner
30:07
DNA Polymerase Attaches Complementary Bases in Fragments
31:06
DNA Polymerase Replaces RNA Primers
31:22
DNA Ligase Connects Fragments Together
31:44
DNA Replication Illustration
32:25
'Junk' DNA
45:02
Only 2% of the Human Genome Codes for Protein
45:11
What Does Junk DNA Mean to Us?
46:52
DNA Technology Uses These Sequences
49:20
RNA

51m 59s

Intro
0:00
The Central Dogma
0:04
Transcription
0:57
Translation
1:11
RNA: Its Role and Characteristics
2:02
Ribonucleic Acid
2:06
How It Is Different From DNA
2:59
DNA and RNA Differences
5:00
Types of RNA
6:01
Messenger RNA
6:15
Ribosomal RNA
6:49
Transfer RNA
7:52
Others
8:54
Transcription
9:26
Process in Which RNA is Made From a Gene in DNA
9:30
How It's Done
9:55
Summary of Steps
10:35
Transcription Steps
11:54
Initiation
11:57
Elongation
15:57
Termination
18:10
RNA Processing
21:35
Pre-mRNA
21:37
Modifications
21:53
Translation
27:01
Process in Which mRNA Binds with a Ribosome and tRNA and rRNA Assist
27:03
Summary of Steps
28:39
Translation the mRNA Code
28:59
Every Codon in mRNA Gets Translated to an Amino Acid
29:14
Chart Providing the Resulting Translation
29:19
Translation Steps
32:20
Initiation
32:23
Elongation
35:31
Termination
38:43
Mutations
40:22
Code in DNA is Subject to Change
41:00
Why Mutations Happen
41:23
Point Mutation
43:16
Insertion / Deletion
47:58
Duplications
50:03
Genetics, Part I

1h 15m 17s

Intro
0:00
Gregor Mendel
0:05
Father of Genetics
0:39
Experimented with Crossing Peas
1:02
Discovered Consistent Patterns
2:37
Mendel's Laws of Genetics
3:10
Law of Segregation
3:20
Law of Independent Assortment
5:07
Genetics Vocabulary #1
6:28
Gene
6:42
Allele
7:18
Homozygous
8:25
Heterozygous
9:39
Genotype
10:15
Phenotype
11:01
Hybrid
11:53
Pure Breeding
12:28
Generation Vocabulary
13:03
Parental Generation
13:25
1st Filial
13:58
2nd Filial
14:06
Punnett Squares
15:07
Monohybrid Cross
18:52
Mating Pure-Breeding Peas in the P Generation
19:09
F1 Cross
21:31
Dihybrid Cross Introduction
23:42
Traced Inheritance of 2 Genes in Pea Plants
23:50
Dihybrid Cross Example
26:07
Phenotypic Ratio
31:34
Incomplete Dominance
32:02
Blended Inheritance
32:27
Example
32:35
Epistasis
35:05
Occurs When a Gene Has the Ability to Completely Cancel Out the Expression of Another Gene
35:10
Example
35:30
Multiple Alleles
40:12
More Than Two Forms of Alleles
40:23
Example
41:06
Polygenic Inheritance
46:50
Many Traits Get Phenotype From the Inheritance of Numerous Genes
46:58
Example
47:26
Test Cross
51:53
In Cases of Complete Dominance
52:03
Test Cross Demonstrates Which Genotype They Have
52:52
Sex-Linked Traits
53:56
Autosomes
54:21
Sex Chromosomes
54:57
Genetic Disorders
59:31
Autosomal Recessive
1:00:00
Autosomal Dominant
1:06:17
Sex-Linked Recessive
1:09:19
Sex-Linked Dominant
1:13:41
Genetics, Part II

49m 57s

Intro
0:00
Karotyping
0:04
Process to Check Chromosomes for Abnormal Characteristics
0:08
Done with Cells From a Fetus
0:58
Amniocentesis
1:02
Normal Karotype
2:43
Abnormal Karotype
4:20
Nondisjunction
5:14
Failure of Chromosomes to Properly Separate During Meiosis
5:16
Nondisjunction
5:45
Typically Causes Chromosomal Disorders Upon Fertilization
6:33
Chromosomal Disorders
10:52
Autosome Disorders
11:01
Sex Chromosome Disorders
14:06
Pedigrees
20:29
Visual Depiction of an Inheritance Pattern for One Gene in a Family's History
20:30
Symbols
20:46
Trait Being Traced is Depicted by Coloring in the Individual
21:58
Pedigree Example #1
22:26
Pedigree Example #2
25:02
Pedigree Example #3
27:23
Environmental Impact
30:24
Gene Expression Is Often Influenced by Environment
30:25
Twin Studies
30:35
Examples
31:45
Genetic Engineering
36:03
Genetic Transformation
36:17
Restriction Enzymes
39:09
Recombinant DNA
40:37
Gene Cloning
41:58
Polymerase Chain Reaction
43:13
Gel Electrophoresis
44:37
Transgenic Organisms
48:03
IV. History of Life
Evolution

1h 47m 19s

Intro
0:00
The Scientists Behind the Theory
0:04
Fossil Study and Catastrophism
0:18
Gradualism
1:13
Population Growth
2:00
Early Evolution Thought
2:37
Natural Selection As a Sound Theory
8:05
Darwin's Voyage
8:59
Galapagos Islands Stop
9:15
Theory of Natural Selection
11:24
Natural Selection Summary
12:37
Populations have Enormous Reproductive Potential
13:45
Population Sizes Tend to Remain Relatively Stable
14:55
Resources Are Limited
16:51
Individuals Compete for Survival
17:16
There is Much Variation Among Individuals in a Population
17:36
Much Variation is Heritable
18:06
Only the Most Fit Individuals Survive
18:27
Evolution Occurs As Advantageous Traits Accumulate
19:23
Evidence for Evolution
19:47
Molecular Biology
19:53
Homologous Structures
22:55
Analogous Structures
26:20
Embryology
29:36
Paleontology
34:54
Patterns of Evolution
40:14
Divergent Evolution
40:37
Convergent Evolution
43:15
Co-Evolution
46:07
Gradualism vs. Punctuated Equilibrium
49:56
Modes of Selection
52:25
Directional Selection
54:40
Disruptive Selection
56:38
Stabilizing Selection
58:07
Artificial Selection
59:56
Sexual Selection
1:02:13
More on Sexual Selection
1:03:00
Sexual Dimorphism
1:03:26
Examples
1:04:50
Notes on Natural Selection
1:09:41
Phenotype
1:10:01
Only Heritable Traits
1:11:00
Mutations Fuel Natural Selection
11:39
Reproductive Isolation
1:12:00
Temporal Isolation
1:12:59
Behavioral Isolation
1:14:17
Mechanical Isolation
1:15:13
Gametic Isolation
1:16:21
Geographic Isolation
1:16:51
Reproductive Isolation (Post-Zygotic)
1:18:37
Hybrid Sterility
1:18:57
Hybrid Inviability
1:20:08
Hybrid Breakdown
1:20:31
Speciation
1:21:02
Process in Which New Species Forms From an Ancestral Form
1:21:13
Factors That Can Lead to Development of a New Species
1:21:19
Adaptive Radiation
1:24:26
Radiating of Various New Species
1:24:28
Changes in Appearance
1:24:56
Examples
1:24:14
Hardy-Weinberg Theorem
1:27:35
Five Conditions
1:28:15
Equations
1:33:55
Microevolution
1:36:59
Natural Selection
1:37:11
Genetic Drift
1:37:34
Gene Flow
1:40:54
Nonrandom Mating
1:41:06
Clarifications About Evolution
1:41:24
A Single Organism Cannot Evolve
1:41:34
No Single Missing Link with Human Evolution
1:43:01
Humans Did Not Evolve from Chimpanzees
1:46:13
Human Evolution

47m 31s

Intro
0:00
Primates
0:04
Typical Primate Characteristics
1:12
Strepsirrhines
3:26
Haplorhines
4:08
Anthropoids
5:03
New World Monkeys
5:15
Old World Moneys
6:20
Hominoids
6:51
Hominins
7:51
Hominins
8:46
Larger Brains
8:53
Thinner, Flatter Face
9:02
High Manual Dexterity
9:30
Bipedal
9:41
Australopithecines
12:11
Earliest Fossil Evidence for Bipedalism
12:24
Earliest Australopithecines
13:06
Lucy
13:35
The Genus 'Homo'
15:20
Living and Extinct Humans
16:46
Features
16:52
Tool Use
17:09
Homo Habilis
17:38
2.4 - 1.4 mya
18:38
Handy Human
19:19
Found In Africa
19:33
Homo Ergaster
20:11
1.8 - 1.2 mya
20:14
Features
20:25
Found In and Outside of Africa
20:41
Most Likely Hunted
21:03
Homo Erectus
21:32
1.8 - 0.4 mya
22:04
Upright Human
22:49
Found in Africa, Asia, and Europe
22:52
Features
22:57
Used Fire
23:07
Homo Heidelbergensis
23:45
1.3 - 0.2 mya
23:50
Transitional Form
24:22
Features
24:36
Homo Sapiens Neanderthalensis
24:56
0.3 - 0.2 mya
25:23
Neander Valley
25:31
Found in Europe and Asia
21:53
Constructed Complex Structures
27:50
Modern Human and Neanderthal
28:50
Homo Sapiens Sapiens
29:34
195,000 Years Ago - Present
29:37
Humans Most Likely Evolved Once
29:50
Features
30:26
Creative and More Control Over the Environment
30:37
Homo Floresiensis
31:36
18,000 Years Old
31:40
The Hobbit
32:09
Brain and Body Proportions are Similar to Australopithecines
32:16
Human Migration Summary
32:49
Origins of Life

40m 58s

Intro
0:00
Brief History of Earth
0:05
About 4.5 Billion Years Old
0:13
Started Off as a Fiery Ball of Hot Volcanic Activity
1:12
Atmospheric Gas of Early Earth
2:20
Gases Expelled Out of Volcanic Vents
3:10
Building Blocks to Organic Compounds
4:47
Miller-Urey Experiment (1953)
5:41
Stanley Miller and Harold Urey
5:48
Amino Acids Were Found in the Sterile Water Beneath
7:27
Protobionts
8:07
Ancestors of Cells as We Know Them
8:19
Lipid Bubbles with Organic Compounds Inside
8:32
Origin of DNA
12:07
First Cells
12:12
RNA Originally Coded for Protein
12:44
DNA Allows for Retention and a Checking for Errors
12:55
Oxygen Surge
14:57
Photosynthesis Changes Oxygen Gas in Atmosphere
16:36
Cells Absorb Solar Energy with Pigment and Could Make Sugars and Release Oxygen
17:05
Endosymbiotic Theory
18:22
First Eukaryote was Born
19:54
First Proposed by Lynn Margulis
22:43
Multicellular Origins
23:08
Cells That Kept Close Quarters and Stayed Attached Had Safety in Numbers
23:28
Hypothesis
23:45
Cambrian Explosion
26:22
Explosion of Species
27:10
Theory and Snowball Earth
28:24
Timeline of Major Events
32:00
Biogenesis

27m 25s

Intro
0:00
Spontaneous Generation
0:04
Spontaneous Generation
0:14
Pseudoscience
1:45
Individuals Who Sought to Disprove This Theory
2:49
Francesco Redi's Experiment
3:33
17th Century Italian Scientist
3:36
Wanted to Debunk the Theory That Maggots Emerge From Rotting Raw Meat
3:48
Lazzaro Spallanzani's Experiment
6:33
18th Century Italian Scientist
6:36
Wanted to Demonstrate That Microbes Could Be Airborne
6:58
Louis Pasteur's Experiment
9:47
19th Century French Scientist
9:51
Disprove Spontaneous Generation
11:17
Pasteur's Vaccine Discovery
13:47
Motivation to Discover a Way to Immunize People Against Disease
14:00
Cholera Bacteria
14:42
Vaccine Explanation
16:42
Inactive Versions of the Virus are Generated in a Culture
16:47
Antigens Injected Into the Person
17:45
Common Immunizations
22:00
Effectiveness
22:03
No Proof That Vaccines Cause Autism
26:33
V. Diversity of Life
Taxonomy

35m 21s

Intro
0:00
Ancient Classification
0:04
Start of Classification Systems
0:56
How Plants and Animals Were Split Up
2:46
Used in Europe Until 1700s
3:27
Modern Classification
3:52
Carolus Linnaeus
3:58
Taxonomy
5:15
Taxonomic Groups
6:57
Domain
7:14
Kingdom
7:29
Phylum
7:39
Class
7:49
Order
8:02
Family
8:09
Genus
8:25
Species
8:45
Binomial Nomenclature
12:10
Genus Species
12:22
Naming System Rules
12:49
Advantages and Disadvantages to Taxonomy
14:56
Advantages
15:00
Disadvantages
17:53
Domains
20:31
Domain Archaea
21:10
Domain Bacteria
21:19
Domain Eukarya
21:43
Extremophiles
22:48
Kingdoms
25:09
Kingdom Archaebacteria
25:17
Kingdom Eubacteria
25:25
Kingdom Protista
25:52
Kingdom Plantae, Fungi, Animalia
27:18
Cladograms
28:07
Relates Evolution to Phylogeny
28:12
Characteristics Lead to Splitting Off Groups of Organisms
28:20
Viruses

44m 25s

Intro
0:00
Virus Basics
0:04
Non-Living Structures have the Potential to Harm Life on Earth
0:14
Made of Nucleic Acids Wrapped in a Protein Coat
2:15
5 to 300 nm Wide
3:12
Virus Structure
4:29
Icosahedral
4:41
Spherical
5:33
Bacteriophage
6:20
Helical
8:56
How Do They Invade Cells?
11:24
Viruses Can Fool Cells to Let Them In
11:27
Viruses Use the Organelles of the Host
12:29
Viruses are Host Specific
12:57
Viral Cycle
16:18
Lytic Cycle
16:34
Lysogenic Cycle
18:53
Connection Between Lytic/ Lysogenic
23:01
Retroviruses
30:04
Process is Backwards
30:52
Reverse Transcriptase
31:08
Example
31:47
HIV/ AIDS
32:38
Human Immunodeficiency Virus
32:42
Acquired Immunodeficiency Syndrome
36:27
Smallpox: A Brief History
37:06
One of the Most Harmful Viral Diseases in Human History
37:09
History
37:53
Prions
41:32
Infectious Proteins That Damage the Nervous System
41:33
Cause Transmittable Spongiform Encephalopathies
41:51
No Known Cure
43:42
Bacteria

46m 1s

Intro
0:00
Archaebacteria
0:04
Thermophiles
1:10
Halophiles
2:06
Acidophiles
2:29
Methanogens
2:59
Archaea and Bacteria Compared to Eukarya
4:25
Archaea and Eukarya
4:36
Bacteria and Eukarya
5:37
Eubacteria
6:35
Nucleoid Region
7:02
Peptidoglycan
7:21
Binary Fission
8:08
No Membrane-Bound Organelles
8:59
Bacterial Shapes
10:19
Coccus
10:26
Bacillus
12:07
Spirillum
12:44
Bacterial Cell Walls
13:17
Gram Positive
13:47
Gram Negative
15:09
Bacterial Adaptations
16:13
Capsule
16:18
Fimbriae
17:51
Conjugation
18:30
Endospore
21:30
Flagella
23:49
Metabolism
24:36
Benefits of Bacteria
27:28
Mutualism
27:32
Connections to Human Life
30:56
Diseases Caused by Bacteria
35:05
STDs
35:15
Respiratory
36:04
Skin
37:15
Digestive Tract
38:00
Nervous System
38:27
Systemic Diseases
39:09
Antibiotics
40:26
Drugs That Block Protein Synthesis
40:40
Drugs That Block Cell Wall Production
41:07
Increased Bacterial Resistance
41:36
Protists

32m 46s

Intro
0:00
Kingdom Protista Basics
0:04
Unicellular and Multicellular
0:28
Asexual and Sexual
0:48
Water and Land
1:06
Resemble Other Life Forms
1:32
Protist Origin
2:04
Evolutionary Bridge Between Bacteria and Multicellular Eukaryotes
2:06
Protist Ancestors
2:27
Protist Debate
4:18
One Kingdom
4:30
Some Scientists Group Into Separate Kingdoms Based on Genetic Links
4:37
Plant-like Protists
6:03
Photoautotrophs
6:12
Green Algae
6:44
Red Algae
7:12
Brown Algae
7:57
Golden Algae
9:10
Dinoflagellates
9:20
Diatoms
9:41
Euglena
10:17
Euglena Structure
10:39
Ulva Life Cycle
12:08
Fungi-Like Protists
15:39
Heterotrophs That Feed on Decaying Organic Matter
15:41
Found Anywhere with Moisture and Warmth
16:04
Cellular Slime Mold Life Cycle
17:34
Animal-like Protists
21:45
Heterotrophs That Eat Live Cells
21:50
Motile
22:03
Amoeba Life Cycle
25:24
How Protists Impact Humans
29:09
Good
29:16
Bad
32:18
Plants, Part I

54m 22s

Intro
0:00
Kingdom Plantae Characteristics
0:05
Cuticle
0:38
Vascular Bundles
1:18
Stomata
2:51
Alternation of Generations
4:16
Plant Origins
5:58
Common Ancestor with Green Algae
6:03
Appeared on Earth 400 Million Years Ago
7:28
Non-Vascular Plants
8:17
Bryophytes
8:45
Anthoworts
9:12
Hepaticophytes
9:19
Bryophyte (Moss) Life Cycle
9:30
Dominant Gametophyte
9:38
Illustration Explanation
9:58
Seedless Vascular Plants
15:26
Do Not Reproduce With Seeds
15:33
Sori
15:42
Lycophytes
15:54
Pterophytes
16:30
Pterophyte (Fern) Life Cycle
17:05
Dominant Generation
17:08
Produce Motile Sperm
17:17
Seed Plants
23:17
Most Vascular Plants Have Seeds
23:25
Cotyledons
23:43
Gymnosperm vs. Angiosperm
24:50
Divisions
25:48
Coniferophytes (Cone-Bearing Plants)
27:05
Examples
27:07
Evergreen or Deciduous
27:44
Gymnosperms
28:26
Economic Importance
29:28
Conifer Life Cycle
30:10
Dominant Generation
30:13
Cones Contain the Gametophyte
30:25
Illustration Explanation
30:31
Anthophytes (Flowering Plants)
38:01
Every Plant That Has Flowers
38:03
Angiosperms
38:28
Various Life Spans
38:03
Flower Anatomy
40:25
Female Parts
40:54
Male Parts
42:49
Flowering Plant Life Cycle
44:48
Dominant Generation
44:56
Flowers Contain the Gametophyte
45:05
Plants, Part II

44m 40s

Intro
0:00
Plant Cell Varieties
0:05
Parenchyma
0:11
Collenchyma
1:37
Sclerenchyma
2:03
Specialized Tissues
2:56
Plant Tissues
3:17
Meristematic Tissue
3:21
Dermal Tissue
6:46
Vascular Tissues
8:45
Ground Tissue
13:56
Roots
14:24
Root Cap
15:59
Cortex
16:17
Endodermis
17:02
Pericycle
17:42
Taproot
18:11
Fibrous
18:20
Modified
18:49
Stems
19:49
Tuber
21:43
Rhizome
21:58
Runner
22:12
Bulb and Corm
22:49
Leaves
23:06
Photosynthesis
23:09
Leaf Parts
23:32
Gas Exchange
25:55
Transpiration
26:25
Seeds
27:41
Cotyledons
28:42
Seed Coat
29:29
Endosperm
29:37
Embryo
30:10
Radicle
30:27
Epicotyl
31:57
Fruit
33:49
Fleshy Fruits
34:46
Aggregate Fruits
35:17
Multiple Fruits
35:50
Dry Fruits
36:27
Plant Hormones
37:44
Definition or Hormones
37:48
Examples
38:12
Plant Responses
40:42
Tropisms
41:00
Nastic Responses
43:04
Fungi

26m 20s

Intro
0:00
Fungi Basics
0:03
Characteristics
0:09
Closely Related to Kingdom Animalia
2:33
Fungal Structure
2:58
Hypae
3:03
Mycelium
5:00
Spore
5:24
Reproductive Strategies
6:15
Fragmentation
6:23
Budding
6:35
Spore Production
7:03
Zygomycota (Molds)
7:50
Sexual Reproduction
8:04
Dikaryotic
9:47
Stolons
10:32
Rhizoids
10:53
Ascomycota (Sac Fungi)
11:43
Largest Phylum of Fungi on Earth
11:47
Ascus
12:20
Conidia
12:30
Example
12:46
Basidiomycota (Club Fungi)
14:51
Basidium
15:14
Common Structures In These Fungi
15:37
Examples
16:17
Deuteromycota (Imperfect Fungi)
17:25
No Known Sexual Life Cycle
17:31
Penicillin
18:00
Benefits of Fungi
18:51
Mutualism
18:56
Food
21:41
Medicines
22:30
Decomposition
23:08
Fungal Infections
23:38
Athlete's Foot
23:44
Ringworm
24:09
Yeast Infections
24:27
Candidemia
24:56
Aspergillus
25:15
Fungal Meningitis
25:44
Animals, Part I

35m 28s

Intro
0:00
Animal Basics
0:05
Multicellular Eukaryotes
0:12
Motility
0:27
Heterotrophic
0:47
Sexual Reproduction
0:57
Symmetry
1:14
Gut
1:26
Cephalization
1:40
Segmentation
1:53
Sensory Organs
2:09
Reproductive Strategies
3:07
Gonads
3:17
Fertilization
4:01
Asexual
4:53
Animal Development
7:27
Zygote
7:29
Blastula
7:50
Gastrula
9:07
Embryo
12:57
Symmetry
13:17
Radial Symmetry
14:14
Bilateral Symmetry
15:26
Asymmetry
16:34
Body Cavities
17:22
Coelom
17:24
Acoelomates
18:39
Pseudocoelomates
19:15
Coelomates
19:40
Major Animal Phyla
20:47
Phylum Porifera
21:15
Phylum Cnidaria
21:33
Phylum Platyhelmininthes, Nematoda, and Annelida
21:44
Phylum Rotifera
21:56
Phylum Mollusca
22:13
Phylum Arthropoda
22:34
Phylum Echinodermata
22:48
Phylum Chordata
23:18
Phylum Porifera
25:15
Sponges
25:23
Oceanic or Aquatic
26:07
Adults are Sessile
26:26
Structure
27:09
Sexual or Asexual Reproduction
28:31
Phylum Cnidaria
28:49
Sea Jellies, Anemonse, Hydrozoans, and Corals
28:57
Mostly Oceanic
30:42
Body Types
31:32
Cnidocytes
33:06
Nerve Net
34:55
Animals, Part II

48m 42s

Intro
0:00
Phylum Platyhelminthes
0:04
Flatworms
0:14
Acoelomates
0:33
Terrestrial, Oceanic, or Aquatic
0:46
Simple Nervous System
2:46
Reproduction
3:38
Phylum Nematoda
4:20
Unsegmented Roundworms
4:25
Pseudocoelomates
4:34
Terrestrial, Oceanic, or Aquatic
4:53
Full Digestive Tract
5:29
Reproduction
7:07
C. Elegans
7:24
Phylum Annelida
8:11
Segmented Roundworms
8:20
Terrestrial, Oceanic, or Aquatic
8:42
Full Digestive Tract
8:56
Accordion-like Movement
11:26
Simple Nervous System
12:31
Sexual Reproduction
13:40
Class Oligochaeta
14:47
Class Polychaeta
14:56
Class Hirudinea
15:13
Phylum Rotifera
16:11
Pseudocoelomates
16:26
Terrestrial, Aquatic
16:42
Digestive Tract
16:56
Phylum Mollusca
18:55
Snails, Slugs, Clams, Oysters
19:00
Terrestrial, Oceanic, or Aquatic
19:14
Mantle
19:29
Full Digestive Tract with Specialized Organs
21:10
Sexual Reproduction
24:29
Major Classes
24:58
Phylum Arthropoda
28:16
Insects, Arachnids, Crustaceans
28:19
Terrestrial, Oceanic, or Aquatic
28:41
Head, Thorax, Abdomen
28:50
Excretion with Malpighian Tubes
32:48
Arthropod Groups
34:06
Phylum Echinodermata
38:32
Sea Stars, Sea Urchins, Sand Dollars, Sea Cucumbers
38:37
Oceanic or Aquatic
39:36
Water Vascular System
39:43
Full Digestive Tract
40:38
Sexual Reproduction
42:01
Phylum Chordata
42:16
All Vertebrates
42:22
Terrestrial, Oceanic, or Aquatic
42:40
Main Body Parts
42:49
Mostly in Subphylum Vertebrata
44:54
Examples
45:14
Animals, Part III

35m 45s

Intro
0:00
Characteristics of Subphylum Vertebrata
0:04
Vertebral Column
0:16
Neural Crest
0:38
Internal Organs
1:24
Fish Characteristics
2:05
Oceanic or Aquatic
2:16
Locomotion with Paired Fins
3:15
Gills
4:18
Fertilization
8:14
Movement
8:30
Fish Classes
8:58
Jawless Fishes
9:06
Cartilaginous Fishes
10:07
Bony Fishes
10:46
Amphibian Characteristics
12:22
Tetrapods
12:29
Moist Skin
14:22
Circulation
14:39
Nictitating Membrane
16:36
Tympanic Membrane
16:56
External Fertilization is Typical
17:34
Amphibian Orders
18:20
Order Anura
18:27
Order Caudata
19:15
Order Gymnophiona
19:59
Reptile Characteristics
20:31
Dry, Scaly Skin
20:37
Lungs for Gas Exchange
22:00
Terrestrial, Oceanic, Aquatic
22:12
Ectothermic
23:07
Internal Fertilization
24:13
Reptile Orders
26:28
Order Squamata
26:33
Order Crocodilia
27:32
Order Testudinata
27:55
Order Sphenodonta
28:30
Bird Characteristics
28:43
Feathers
29:42
Lightweight Bones
31:33
Lungs with Air Sacs
32:25
Endothermic
33:47
Internal Fertilization
34:03
Bird Orders
34:13
Order Passeriformes
34:29
Order Ciconiiformes
34:46
Order Sphenisciformes
34:55
Order Strigiformes
35:20
Order Struthioniformes
35:25
Order Anseriformes
35:38
Mammals

38m 39s

Intro
0:00
Mammary Glands and Hair
0:04
Class Mammalia Name
0:20
Hair Functions
1:53
Metabolic Characteristics
3:58
Endothermy
4:01
Feeding
4:48
Mammalian Organs
8:43
Respiratory System
8:47
Circulation
9:26
Brain and Senses
10:29
Glands
11:56
Mammalian Reproduction
12:55
Live Birth
13:03
Placental
13:17
Marsupial
14:41
Gestation Periods
16:07
Infraclass Marsupialia
17:42
Australia
17:59
Uterus/ Pouch
18:33
Origins
18:53
Examples
19:24
Order Monotremata
20:21
Egg Layers
20:25
Platypus, Echidna
20:55
Shoulder Area Has a Reptilian Bone Structure
21:07
Order Insectivora
22:21
Insectivores
22:23
Pointy Snouts
22:32
Burrowing
22:53
Examples
23:10
Order Chiroptera
23:32
True Flying Mammalian Order
23:38
Wings
23:59
Feeding
24:21
Examples
25:08
Order Xenarthra
25:14
Edentata
25:18
No Teeth
25:23
Location
25:50
Examples
25:55
Order Rodentia
26:33
40% of Mammalian Species
26:38
2 Pairs of Incisors
26:45
Examples
27:28
Order Lagomorpha
28:06
Herbivores
28:30
Examples
28:41
Order Carnivora
29:19
Teeth
29:36
Examples
29:42
Order Proboscidea
30:37
Largest Living Terrestrial Mammals
30:40
Trunks
30:48
Tusks
31:12
Examples
31:33
Order Sirenia
32:01
Large, Slow Moving Aquatic Mammals
32:15
Flippers
32:26
Herbivores
32:37
Examples
32:42
Order Cetacea
32:46
Large, Mostly Hairless Aquatic Mammals
32:50
Flippers
33:06
Fluke
33:18
Blowhole
33:29
Examples
34:10
Order Artiodactyla
34:30
Even-Toed Hoofed Mammals
34:33
Herbivores
34:37
Sometimes Grouped with Cetaceans
34:52
Examples
35:35
Order Perissodactyla
35:57
Odd-Toed Hoofed Mammals
36:00
Herbivores
36:12
Examples
36:27
Order Primates
36:30
Largest Brain-to-Body Ratio
36:35
Arboreal
37:03
Nails
37:33
Examples
38:29
Animal Behavior

29m 55s

Intro
0:00
Behavior Overview
0:04
Behavior
0:08
Origin of Behavior
0:36
Competitive Advantage
1:26
Innate Behaviors
2:05
Genetically Based
2:07
Instinct
2:13
Fixed Action Pattern
3:31
Learned Behavior
5:13
Habituation
5:26
Classical Conditioning
6:31
Operant Conditioning
7:51
Imprinting
10:17
Learned Behavior That Can Only Occur in a Specific Time Period
10:20
Sensitive Period
10:28
Cognitive Behaviors
11:53
Thinking, Reasoning, and Processing Information
12:02
Examples
12:22
Competitive Behaviors
14:40
Agonistic Behavior
14:46
Dominance Hierarchies
15:23
Territorial Behaviors
16:19
More Types of Behavior
17:05
Foraging Behaviors
17:08
Migratory Behaviors
17:53
Biological Rhythms
19:15
Communication Behaviors
20:37
Pheromones
20:52
Auditory Communication
22:18
Courting and Nurturing Behaviors
23:42
Courting Behaviors
23:45
Nurturing Behaviors
26:04
Cooperative Behaviors
26:47
Benefit All Members of the Group
27:01
Example
27:08
VI. Ecology
Ecology, Part I

1h 7m 26s

Intro
0:00
Ecology Basics
0:05
Ecology
0:18
Biotic vs. Abiotic Factors
1:25
Population
2:23
Community
2:45
Ecosystem
3:04
Biosphere
3:27
Individuals and Survival
4:13
Habitat
4:23
Niche
4:37
Symbiosis
7:07
Obtaining Energy
11:14
Producers
11:24
Consumers
13:31
Food Chain
17:11
Model to Illustrate How Matter Moves Through Organisms in an Ecosystem
17:15
Examples
18:31
Food Web
20:29
Keystone Species
22:55
Three Ecological Pyramids
27:28
Pyramid of Energy
27:38
Pyramid of Numbers
31:39
Pyramid of Biomass
34:09
The Water Cycle
37:24
The Carbon Cycle
40:19
The Nitrogen Cycle
43:34
The Phosphorus Cycle
46:42
Population Growth
49:35
Reproductive Patterns
51:58
Life History Patterns Vary
52:10
r-Selection
53:30
K-Selection
56:55
Density Factors
59:02
Density-Dependent Factors
59:29
Density-Independent Factors
1:02:21
Predator / Prey Relationships
1:03:59
Ecology, Part II

50m 50s

Intro
0:00
Mimicry
0:05
Batesian Mimicry
0:38
Müllerian Mimicry
1:53
Camouflage
3:23
Blend In with Surroundings
3:38
Evade Detection by Predators
3:43
Succession
5:22
Primary Succession
5:40
Secondary Succession
7:44
Biomes
9:31
Terrestrial
10:08
Aquatic / Marine
10:05
Desert
11:20
Annual Rainfall
11:24
Flora
13:35
Fauna
14:15
Tundra
14:49
Annual Rainfall
15:00
Permafrost
15:50
Flora
16:06
Fauna
16:40
Taiga (Boreal Forest)
16:59
Annual Rainfall
17:14
Largest Terrestrial Biome
17:33
Flora
18:37
Fauna
18:49
Temperate Grassland
19:07
Annual Rainfall
19:28
Flora
20:14
Fauna
20:18
Tropical Grassland (Savanna)
20:41
Annual Rainfall
21:01
Flora
21:56
Fauna
22:00
Temperate Deciduous Forest
22:19
Annual Rainfall
23:11
Flora
23:45
Fauna
23:50
Tropical Rain Forest
24:11
Annual Rainfall
24:16
Flora
27:15
Fauna
27:49
Lakes
28:05
Eutrophic
28:21
Oligotrophic
28:29
Zones
29:34
Estuaries
32:56
Area Where Freshwater and Salt Water Meet
33:00
Mangrove Swamps
33:12
Nutrient Traps
33:52
Organisms
34:24
Marine
34:50
Euphotic Zone
35:16
Pelagic Zone
37:11
Abyssal Plain
38:15
Conservation Summary
40:03
Biodiversity
40:33
Habitat Loss
44:06
Pollution
44:55
Climate Change
47:03
Global Warming
47:06
Greenhouse Gases
47:48
Polar Ice Caps
49:01
Weather Patterns
50:00
VII. Laboratory
Laboratory Investigation I: Microscope Lab

24m 51s

Intro
0:00
Light Microscope Parts
0:06
Microscope Use
6:25
Mount the Specimen
6:28
Place Slide on Stage
7:29
Ensure Specimen is Above Light Source
8:11
Lowest Objective Lens Faces Downward
8:34
Focus on the Image
9:36
Adjust the Nosepiece If Needed
9:49
Re-Focus
9:57
Human Skin Layers
10:42
Plants Cells
13:43
Human Lung Tissue
15:20
Euglena
18:26
Plant Stem
20:43
Mold
22:57
Laboratory Investigation II: Egg Lab

11m 26s

Intro
0:00
Egg Lab Introduction
0:06
Purpose
0:09
Materials
0:37
Time
1:24
Day 1
1:28
Day 2
3:59
Day 3
6:05
Analysis
7:50
Osmosis Connection
10:24
Hypertonic
10:36
Hypotonic
10:49
Laboratory Investigation III: Carbon Dioxide Production

14m 34s

Intro
0:00
Carbon Dioxide Introduction
0:06
Purpose
0:09
Materials
0:56
Time
2:39
Part I
2:41
Put Water in Large Beaker
3:09
Exhale Into the Water
3:15
Add a Drop of Phenolphthalein
4:31
Add NaOH
5:33
Record the Amount of Drops
6:10
Part II
6:24
Add HCL
6:39
Exercise for Five Minutes
7:26
Return and Re-Do the Exhaling
7:58
Analysis
9:11
Aerobic Respiration Connection
13:18
As Aerobic Respiration Occurs In Cells, Carbon Dioxide Is Produced
13:21
Increase Output of Carbon Dioxide
13:29
Number of Exhalations Increase
14:17
Laboratory Investigation IV: DNA Extraction Lab

10m 38s

Intro
0:00
DNA Lab Introduction
0:06
Purpose
0:09
Materials
0:45
Time
2:03
Part I
2:06
Pour Sports Drink Into the Small Cup
2:08
When Time Expires, Spit Into the Cup
2:53
Add Cell Lysate Solution
3:21
Let it Sit for a Couple Minutes
4:04
Part II
4:10
Slowly Add Cold Ethanol
4:13
DNA Will Creep Up Into the Ethanol Layer
5:01
Analysis
5:59
DNA Structure Connection
8:49
DNA is Microscopic
8:54
Visible DNA
9:39
Extracted DNA
9:49
Laboratory Investigation V: Onion Root Tip Mitosis Lab

13m 12s

Intro
0:00
Mitosis Lab Introduction
0:06
Purpose
0:09
Materials
0:57
Time
1:42
Part I
1:49
Mount the Slide and Zoom Into the Root Apical Meristem
1:50
Zoom In
3:00
Count the Cells in Each Phase
3:09
Record Your Results
3:52
Microscope View Example
3:58
Part II
6:49
Move to Another Part of the Root Apical Meristem
6:55
Count the Phases in this Second Region
7:02
Analysis
9:07
Mitosis Connection
11:17
Rate of Mitosis Varies from Species to Species
11:21
Mitotic Rate Was Higher Since We Used An Actively Dividing Tissue
12:16
Laboratory Investigation VI: Inheritance Lab

13m 55s

Intro
0:00
Inheritance Lab Introduction
0:05
Purpose
0:09
Materials
0:53
Time
2:00
Explanation
2:03
Basic Procedure
5:03
Analysis
8:00
Inheritance Laws Connection
11:23
Law of Segregation
11:31
Law of Independent Assortment
12:49
Laboratory Investigation VII: Allele Frequencies

14m 11s

Intro
0:00
Allele Frequencies Introduction
0:05
Purpose
0:08
Materials
1:34
Time
2:10
Part I
2:12
Part II
7:05
Analysis
7:51
Evolution Connection
10:45
Meant to Stimulate How a Population's Allele Frequencies Change Over Time
10:47
Particular Phenotypes Selected
11:31
Recessive Allele Keeps Dropping
12:18
Laboratory Investigation VIII: Genetic Transformation

16m 42s

Intro
0:00
Genetic Transformation Introduction
0:06
Purpose
0:09
Materials
0:57
Time
3:31
Set-Up
4:18
Starter Culture with E. Coli Colonies
4:21
Just E. Coli
5:37
Ampicillin with No Plasmid
6:24
Ampicillin with Plasmid
7:11
Ampicillin with Plasmid and Arabinose
7:33
Procedure
8:35
Analysis
13:01
Genetic Transformation Connection
14:59
Easier to Transform Bacteria Than a Multicellular Organism
15:03
Desired Trait Can be Expressed from the Bacteria
15:52
Numerous Applications in Medicine
16:04
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Lecture Comments (10)

1 answer

Last reply by: Bryan Cardella
Mon Jan 9, 2017 12:03 PM

Post by Kapil Patel on January 8, 2017

I have a question Mr.Cardella  can you tell me what is the function of Okazaki fragments? and where can we find the Okazaki fragments

1 answer

Last reply by: Bryan Cardella
Thu Jan 14, 2016 2:02 PM

Post by Jinhai Zhang on January 13, 2016

Prof.
Do have lectures explain the telomere of DNA replication?

3 answers

Last reply by: Bryan Cardella
Sat Oct 11, 2014 12:33 PM

Post by King Calculus on October 9, 2014

My question is this:
Is this going on in every cell in my body, even in brain cells?
Also, is the cell structure the same even in my brain? Such as mitochondria and all the DNA replications?
Thanks

0 answers

Post by Lilian Comparini on March 14, 2014

You are not only brilliant and a great teacher, but hilarious as well.

0 answers

Post by Lilian Comparini on March 14, 2014

omg I fell out of my chair laughing at the library with that country song!!

DNA

Lecture Slides are screen-captured images of important points in the lecture. Students can download and print out these lecture slide images to do practice problems as well as take notes while watching the lecture.

  • Intro 0:00
  • DNA: Its Role and Characteristics 0:05
    • Deoxyribonucleic Acid
    • Double Helix
    • Nucleotides
    • Anti-parallel
    • Self-Replicating
    • Codons, Genes, Chromosomes
  • DNA: The Discovery 5:13
    • DNA First Mentioned
    • Bacterial Transformation with DNA
    • Base Pairing Rule
    • DNA is Hereditary Material
    • X-Ray Crystallography Images
    • DNA Structure
  • Nucleotides 12:54
  • The Double Helix 16:34
    • Hydrogen Bonding
    • Backbone of Phosphates and Sugars
    • Strands are Anti-Parallel
  • Nitrogenous Bases 20:52
    • Purines
    • Pyrimidines
  • DNA Replication Overview 24:33
    • DNA Must Duplicate Every Time a Cell is Going to Divide
    • Semiconservative Replication
    • How Does it Occur?
  • DNA Replication Steps 28:39
    • DNA Helicase Unzips Double Stranded DNA
    • RNA Primer is Laid Down
    • DNA Polymerase Attaches Complementary Bases in Continuous Manner
    • DNA Polymerase Attaches Complementary Bases in Fragments
    • DNA Polymerase Replaces RNA Primers
    • DNA Ligase Connects Fragments Together
  • DNA Replication Illustration 32:25
  • 'Junk' DNA 45:02
    • Only 2% of the Human Genome Codes for Protein
    • What Does Junk DNA Mean to Us?
    • DNA Technology Uses These Sequences

Transcription: DNA

Hi, welcome back to www.educator.com, this is the lesson on DNA, its role and characteristics.0000

What is this stuff, what does it do?0008

Most people know basically what DNA is, but we are going into a lot of detail about how it actually functions in cells.0011

DNA stands for deoxyribonucleic acid, there is the DNA.0018

Nucleic acids are general class of compounds, RNA is another kind that is in the next lesson on RNA.0026

DNA contains the instructions for life, it has the codes for how cells do everything.0034

How they maintain homeostasis, how they function, how they physically are?0040

They are able to retain their functionality and form because of DNA.0046

This is the substance that is copied and passed on to daughter cells when it divides, this is what keeps life going.0050

That might seem like common knowledge now, and it is in the scientific community.0058

But 60 years ago, that was not so common.0062

All proteins that cells make can be traced back to the code in the DNA.0066

DNA codes for a protein, proteins are so important cells.0072

It is very prolific in terms of what they do structurally and what they do chemically.0077

Proteins really are how DNA is expressed in cells.0083

Double helix, I put that in capital letters because this is very important.0088

Here is the double helix, this is that classic DNA shape.0092

Helical is spiral, double helix because it is pretty much two spirals attached to the center, this is the shape it is.0097

When we look at this particular structure when we discuss cell division, there is a lot of the double helix in here.0106

This is a heck of a lot bigger than this.0115

Here, we are looking at just several pairs of nucleotides attached together.0119

I will tell you more about nucleotides in a second.0124

In the 46th of these that you would see in a human cell that is about to divide,0126

There are 3 billion nucleotide pairs in all 46 combined.0132

There are hundreds and thousands of genes in these various chromosomes.0139

This structurally is a lot smaller than this.0146

Made of nucleotides, we look down this backbone of DNA on each side, it is nucleotide attached to a nucleotide.0151

Across the center, the nucleotides of these two strands are attached.0158

More details about that later on in the lesson.0163

These strands are antiparallel meaning they go on opposite directions.0166

I am making my arms parallel but it is really like this in DNA.0171

A better way to look at it is that two pens here, two identical looking pens, this would be parallel.0176

Also a mathematics term, I’m making them as parallel as I possibly can.0183

Here is what antiparallel means that this strand, as it curves around,0187

and this one curves connected to it, this is read in the opposite direction.0192

This strand is read in the opposite direction of the strings is attached to.0197

That is what antiparallel means.0202

Do not think it means perpendicular, no it just means these are parallel strands that are read in opposite directions.0204

There are terms about directionality, three prime to five prime coming up later in the lesson.0212

It is self-replicating, enzymes that are naturally found in cells,0216

and DNA actually codes for those enzymes allow DNA to be copied.0220

As long as you have those little nucleotides available,0225

they can be put next to the other strand and new strands can be made.0228

That has to happen before cell divides.0233

Codons, genes, and chromosomes, these terms have to do with what DNA is made up of.0237

I will give you an analogy, a codon is a set of three bases, three nucleotides side by side.0242

You will find these in DNA and RNA.0249

This is like a word in the genetic sentence, a bunch of codons together,0251

it could be a hundred codons or more, can code for a gene.0261

A gene is like a sentence, a bunch of codons together forms a gene.0266

A bunch of genes together, we are talking a lot of genes, would make a whole chapter of this book.0275

A chromosome is kind of like a chapter.0282

Actually this really good book about DNA that is in 23 chapters.0289

Surprise, because 23 is the haploid number for humans, 23 pairs equals our diploid number is 46 chromosomes.0293

Chromosome, a giant package of these genetic sentences,0302

they are made up of words that are known as codons.0307

More about that especially when you get to the RNA lesson.0310

DNA, the discovery, it took many years to get to the point where we really knew0315

this is what DNA is, this is what it does, this is their functions.0319

We are still in the infancy though, if you ask me there is a lot more to be discovered about DNA.0324

There is this recently a new story that I read about that, there is a hidden code that is hidden up to this point,0330

that we did not even know what was going on until further research brought that out to us, that we can really see it.0337

There is a lot going on in the DNA that we still have to tap into, to fully understand it.0345

Miescher, this particular scientist back in the 19th century was able to say,0350

I got the substance inside the cell and I can detect it is not protein, but it is there.0360

He called it nucleon, like he knew it was in the center, in this region called the nucleus.0365

He knew it was not protein because it had these chemicals that are meant to break apart proteins in a cell.0373

The chemicals would not break this down, it would not get rid of it, like it is certainly not protein, it was DNA.0379

That is when it was first mentioned, back in 1869 by Miescher.0387

Griffith 1928, flash forward several decades,0392

this particular scientist proved that it is DNA that can actually transform a bacterium.0397

Generic transformation is when a bacterium sucks up DNA from outside itself and expresses it, changing how it is genetically.0406

He illustrated this with mice, he had a harmful strain of bacteria and a harmless strain of bacteria.0417

The harmful strain, when it was living, and he injected it into the mice, of course they died.0424

They kept dying, when he do that.0429

The harmless strain, when he injected that in to the average mouse, they were fine.0431

Their immune system dealt with it, they did not die.0436

He then took the harmful strain, killed it, and found that,0440

once you kill the harmful strain and inject it in, they cannot do what they do.0446

The bacteria can actually mess with the mouse.0453

This interesting thing happen, when he took the harmful bacteria, killed it, but they combine in a test tube with the harmless bacteria,0456

that harmless bacteria sucked up the DNA from those dead cells.0465

When he injected that mixture, the mice consistently died.0468

He proved that these harmless bacteria took up something from the harmful ones,0472

and they changed themselves, their characteristic is changed.0479

That was bacterial transformation proved in 1928.0482

Chargoff in 1950 figured out this based pairing rule.0486

His research suggested that, when you look at the bases of DNA,0489

the amount of adenines is approximately equal to amount of what is known as thymine the T.0494

A lot of cytosine is approximately equal to the amount of G or guanine.0501

The reason why I say approximately is, when you actually measure the amount of these bases0506

and these are the only 4 bases of DNA in organisms.0511

When you measure the amount of these, let us say 60% of the genome is this and 40% is that.0514

This might not be exactly 30/30, this may not be exactly 20/20.0527

You will see the data that says this is 30.5 and this is 29.5, and a similar pattern with that.0533

As far as we know, it might be a shortcoming of the devices that are measuring those particular bases.0545

But, every time you see a C, cytosine in DNA it is attached to a G.0552

Every time you see adenine it is attached to a T, and vice versa.0557

That is why the amounts equal to each other.0561

Chargoff was not entirely certain at that time, that it meant that they were definitely attached to each other in the center.0563

His research was just showing a trend regarding these bases in many different species that he analyzed.0571

That helped Watson and Crick a few years later, to figure out their discovery.0578

But first, Hershey and Chase in 1952, helped demonstrate that DNA is the hereditary material.0583

They actually showed that, when a virus infects an organism,0589

it is not the proteins of the virus that are being passed on to infect it because the proteins tend to not go in.0598

Some other time they do but in a lot of examples like with bacteria, the proteins do not go in.0605

The DNA is injected in, and they had one set of data where they tagged the proteins,0611

and showed the proteins and virus are not the ones that went in and harmed this bacteria.0618

But in the other set, the other set of data, they tagged the DNA in this.0624

It is the DNA that ends up inside of it, that is what is being passed on, that was making the change.0629

They helped to demonstrate that it is the DNA that is causing this expression to occur,0635

whether it is from a virus or we are talking about our DNA.0642

Roslyn Franklin, unfortunately she did not win the Nobel prize for the discovery of DNA0645

because she had passed away prior to being awarded.0651

She passed away because of a lot of radiation exposure, she took a lot of x-ray images,0656

crystallographic images of DNA samples.0661

That amount of radiation exposure give her cancer, she died very young.0665

The Nobel prize traditionally does not reward posthumous prices to people who are dead.0670

Roslyn Franklin gets a lot of credit now, we know that she did a lot of good.0676

This is a cake and then this is awesome, this is prior for a scientist birthday.0681

They have an image here of her famous image from her crystallography.0686

This particular pattern shows the helical shape of DNA.0694

If you think about how DNA is, there is little piece of it as it twists.0699

It is like this image is focused in right there, you can see the helix.0704

When Watson and Crick saw this, it helped support a theory of theirs about DNA and being a double helix.0710

That was thanks to the research of Ms. Franklin.0717

Watson and Crick, one of the most important discoveries in the 20th century.0720

In 1953 they had this publication of their research about DNA, in terms of the structure of DNA,0724

the bases being attached to the center, the shape of it.0734

They constructed a very accurate metallic model that took up like a whole room, almost from ceiling to floor of the DNA structure.0737

That was a major discovery and they had a good theory about how it is replicated, how the information is passed on.0748

Overtime, their theories that they were not entirely sure a lot of the time have been reinforced because of further research.0756

It is all about standing on the shoulders of giants.0763

The people came before you, building up on what they discovered to figure out more and more about what this awesome molecule is.0766

Nucleotides, this is the building block or monomer for DNA.0775

DNA as a whole would be a polymer, nucleotides those are the building blocks.0780

When we look at what a nucleotide is made up of, it is a phosphate group.0785

We are just going to call it a phosphate, a pentose sugar which just means 5 sided sugar.0790

Specifically, the sugar is called deoxyribose, and then a nitrogenous base.0795

I highlighted phosphate sugar base, and I made this up.0803

Phosphate sugar base, your DNA determines your face.0809

It is a nice little jingle, it can help you remember.0814

Phosphate sugar base, the components of a nucleotide.0816

I even make a little country song out of it.0820

Phosphate sugar base, your DNA determines your face.0822

That is the components of a single nucleotide.0830

In DNA, this sugar would be deoxyribose.0835

It means it has one less oxygen atom than a ribose, deoxiribose.0847

In the corner, instead of having an OH hydroxide group, this particular one we just have an H, stands for the hydrogen.0851

Ribose, in RNA has one more oxygen but that is basically sugars to sugars.0861

Nitrogenous base, this could be any of these except for uracil.0866

I am going to cross this out because this particular base you can see is just in RNA.0872

It is part of nucleotides but not in DNA, you will hear more about that in the lesson on RNA.0879

This base here can be either C or T, you could see that this one has just one little hexagon, there and there.0885

Some of the bases though look like this, they actually are a much larger base.0893

These are called pure, this little hexagon shaped organic compound attached with another little buddy there, a pentagon,0900

and that makes up the whole base adenine or guanine.0907

More about those, a little bit later in the lesson.0911

You can see the difference here between deoxyribose and ribose.0913

As I mentioned, there is that H and OH difference, other than that, they look identical.0916

I just notice a typo, this just said in DNA, when they actually meant RNA.0924

There you go, that ribose in RNA, deoxyribose in DNA.0935

This is a really good illustration, in terms of how it is built.0941

A phosphate is a phosphorus with some oxygen around it.0944

This sugar, it is similar to other sugars you would see.0948

The glucose happens to have 6 carbons, this happens to have 5 that is the pentose.0951

The nitrogenous bases, you can see as you look down one side of the DNA molecule,0956

it is called a poly nucleotide because it is a bunch of nucleotides.0962

It goes phosphate sugar, phosphate sugar, phosphate sugar, phosphate sugar etc.0966

This would be more meaningful later on, but up here when you see this phosphate, this is called the 5 prime end.0972

And down here, whether is not an additional phosphate, they call it the 3 prime end.0979

That does not makes sense right now, but it will be very important when we talk about DNA replication and the formation of RNA,0983

that is part of that anti parallel thing I told you about earlier.0989

The double helix, looking more at the structure of this,0996

it is two strings attached in the center via complimentary nitrogenous bases.1000

It is hydrogen bonds that are keeping those together.1005

When we look at this space filling molecule, they are making a sphere represent every single atom.1009

Here, where we see this yellow with reds, the yellow is the phosphorus and the reds are little oxygen.1016

Here is a phosphate, phosphate, phosphate, in between there are the sugars.1023

In the center where you see the blues, nitrogen is found in the center that is where you have those bases.1028

Just a different way of showing what DNA looks like.1036

Remember, for every adenine in the center, it is attached to a thymine.1039

For every cytosine, it is attached to guanine.1043

The amount of bonds between them is particular.1048

I have an equal sign here, I do not mean that as bonds.1052

I am going to raise the equal sign and show you something that represents hydrogen bonding.1055

These are the bonds between the bases on both sides of the double helix.1062

The amount of hydrogen bonds between A and T is 2.1068

I will make two dotted lines here.1073

1 and 2, it is not the most beautiful thing but you can see it.1080

1 and 2 hydrogen bonds between adenine and thymine.1085

Between cytosine and guanine, you have 3 hydrogen bonds.1088

Why? That is just how it is.1097

They way that these molecules is chemically attract to each other,1100

this one makes 2 H bonds and these two would like to make 3 H bonds.1104

This has something to do with the fact that G and T do not like to be next to each other.1121

They will be next to each other on one side, but here we are talking about attached at the center,1126

from the two different strands.1131

T and G could fit across with each other, but T wants to make 2 bonds, G wants to make 3.1135

The way that I remember how many each set make, 2 bonds, T has 2 lines.1141

To actually write out a T, two lines 1, 2.1148

To write out a G, I know people write G differently, but for me it is three strokes.1152

Three lines to make a G equals 3 bonds to make it with the C.1159

The backbone is made of phosphates and sugar.1164

I pointed that out on previous slide that it is just a sequence of phosphate sugars on the backbone.1166

The rungs of the ladder, the insides, are the bases connected.1172

The strands are anti-parallel and there are some designations for what that means.1177

There is a 3 prime to 5 prime running.1182

On the other side, it is also 3 prime to 5 prime but in opposite directions.1184

This will make more sense, when we talk about DNA replication, 3 prime to 5 prime that is how DNA is read.1190

By read, I mean enzymes are going along and saying here is where the code is.1203

When DNA is made, it is made in the opposite direction 5 prime to 3.1207

Same goes for RNA, when RNA is made in the next lesson, you are going to see it is made from a 5 prime to 3 prime direction.1212

DNA is made in this direction, it is read one way, it is made the other.1223

If you remember the pen example, just think of it this way.1229

Let us say my arm here up on the top, here is the 3 prime end, my elbow is the 5 prime end.1231

It was read from left to right to you, but it is made with the respect to the top strand in the opposite direction.1237

My elbow is the 5 prime end and here is the 3 prime.1245

It is just the opposite directions.1249

Nitrogenous bases, they are truly variable portion of DNA organisms.1253

The amazing thing is, whether you are looking at a fly's DNA, E-coli bacteria DNA, and aardvark’s DNA,1257

a tree, a human, every single organism on this planet has phosphate sugar base making up their DNA.1267

The only thing that is different is the sequence of the bases.1276

Everything else structurally about DNA is the same.1280

It is just a matter of how many A, T, C, G they have and what order.1282

The sequence of bases in the DNA determines the genetic code.1287

The 4 bases of DNA, as you have already seen, are guanine and adenine.1291

Now, we are talking about what makes them purines, and cytosine and thymine what makes them pyrimidines.1294

The purine designation, I will do that in red, this is the big ones, adenine and guanine.1299

How do you remember that the purines are like that as opposed to this, and adenine are guanine are the purines?1308

I have a little hint for that, that will help.1314

This might seem very strange at first but it is helped a lot of my students in the pass.1317

Just follow along with me.1322

Would you agree that little babies are pure, they are pure, they are innocent.1325

Purism, purine, babies tend to be kind of chubby that you can squeeze their cheeks.1331

These are the chubbier of the bases, these are not purines down here but these are their larger bases.1340

Also babies saying gaga, GA.1346

Babies are pure, chubby, and say gaga, that way you can remember that G and A are the purines.1358

Cytosine and thymine, they are pyrimidines, I have a way to remember that.1365

A former student of mine came up with this one.1375

Pyrimid almost looks like the word pyramid, the word for pyramids of Egypt has an A in it, but it is close enough.1377

Pyrimidines, pyramids have coffins and tombs, cats and Tutenkhamun,1388

whatever you want to remember, coffins and tombs, whatever it might be in pyramids.1400

If you look at just this part, what does it look like? A pyramid.1406

C and T, cytosine and thymine, those are the pyrimidines, coffins and tombs.1413

It will help you remember it.1420

Along with the DNA, you always have to have a purine attached to a pyrimidine, you always do, that what keeps it parallel.1422

Imagine, if you had two of these across one another, not only are they are binding,1428

because adenine and guanine want to make different amounts of hydrogen bonds, it would be too wide.1433

The DNA would be like too fat in that part, if you had two pyrimidines across one another, it will be too skinny.1438

To keep it parallel, you are always going to see a wider base with the shorter base, and vice versa.1448

You would not typically have guanine and thymine together because they like making different amounts of bonds.1454

That is why you are going to see guanine and cytosine, adenine and thymine across one another.1460

If you do not have that happening, there has been a mutation, there was a mistake somewhere along, replicating the DNA.1465

DNA replication overview, DNA must be copied or duplicated every time a cell is going to divide.1475

You want to pass on that genetic information to each daughter cell, so they can do the same thing that the parents have been doing.1481

It is known as semi conservative replication.1489

They were the scientist that initially revealed the semi conservative replication.1491

This is how it happens in every single organism that has ever been studied.1497

Bacteria do it this way, plans do it this way, fungi, perimysium, humans, everyone.1501

We all do the semi conservative replication.1508

Since that term semi conservative might be new, let me explain what that means.1510

Let us pretend that this DNA here is the original DNA, it has little bases connected.1516

That is a very simple depiction of DNA.1528

When this DNA gets split apart, and here is the little bases along your A, G, C, and T.1531

There is an enzyme that goes along and makes new DNA, strings together nucleotides.1544

There it is, the red is your new DNA.1551

Here is the red on this side.1554

What ends up going to the daughter cells is half old and half new.1557

You would need to reconnect the bases like that of their.1568

The point of making it is that, this is a semi conservative replication.1571

Other models were proposed, conservative replication not the semi.1576

Conservative replication would be, if the entire original DNA, both strands was conserved.1581

All of that black DNA went into one cell and all the red DNA went to the other,1589

that would be conservative replication, that is not how it happens.1594

This is how it happens where only some of the original DNA is conservative.1597

That is why it is semi conservative, only some of it goes, half of it goes to one cell and half of it goes to the other.1602

Each daughter cell has half newly formed DNA, as well.1608

There is another model called the dispersive model, that one was even more weird.1613

They thought that maybe they are all these little pieces that were passed on,1621

where you would look at one strand that ended up in the daughter cell.1628

It would be like old new, old new, kind of all glued together in different pieces, in sense.1631

That is not true either, semi conservative replication is how it happens.1638

How does replication go, how do you actually copy DNA and put the other new DNA? How does that happen?1643

Short answer is with lots of enzymes, that is really how it happens.1649

The many enzymes is this one right here known as helicase.1655

I will tell you more about that, later on the lesson.1659

DNA polymerase is another important one.1661

This, there are many different versions, many different types of DNA polymerase.1663

This one right here, its job is to link up or bond nucleotides to what is already been assembled on this new strand.1668

DNA polymerase here is doing the same exact thing, just in the opposite direction from the 3 prime 5 prime distinction.1678

In here, you can see what the different colors represent.1684

In real life, are the bases actually different colors?1687

Of course not, but this helps us visualize it so we can understand how these nucleotides are connected to one another.1690

Here, free nucleotides, this is what DNA polymerase is in a sense of grabbing, to put together and form the complement.1698

Here in green, if that is cytosine, DNA polymerase got the guanine there.1705

If that red one is adenine, DNA polymerase got to put thymine right there.1710

That is how it happens, let us get to the steps, the replication steps.1715

On the next slide, I’m going to draw this out for you.1722

I just want to go through a summary of written steps.1725

DNA helicase unzips the double stranded DNA by breaking hydrogen bonds.1730

Remember, hydrogen bonds connect your A and T or C and G.1734

Helicase, specifically DNA helicase, goes in and breaks those bonds, unzips the DNA.1739

You will get something called a replication fork.1745

I will draw that for you on the next page.1747

After that unzipping happens and other enzymes got access to those exposed bases,1750

no longer connected to their complements, an RNA primer is laid down by something called RNA primase.1756

This is an enzyme that puts down a little bit of RNA.1761

That might seem weird because we are making a copy of DNA,1764

why do we got to down an RNA primer, we are not making RNA here.1768

It is because this enzyme, in the next step, DNA polymerase, what it knows how to do is attach nucleotides to nucleotides that are already there.1773

DNA polymerase is unable to just lay down nucleotides were there have not been any yet.1783

An RNA primer is put down so that DNA polymerase 3 has something to attach to.1789

And then later on, the RNA primer will be replaced with DNA by another enzyme.1796

That is why DNA polymerase cannot just lay them down on a bare space.1800

It got to have something to attach them to, that is the RNA primer there.1805

Step 3 is on the leading strand, I will tell you more about that in a second.1808

DNA polymerase 3 attaches complementary bases in a continuous manner to the primer.1812

Complementary bases to what was already there, you know that the original DNA,1819

if you see AAA and lay down TTT, if you see CCG it will lay down GGC, etc.1821

What is this leading strand thing?1829

The leading strand is the side of DNA where the DNA polymerase is going the same direction as helicase.1832

It is going right behind there in a continuous manner, you are going to see it, I will illustrate it on the next page.1840

You will see the lagging strand is on the other side.1846

Since, the strands are not that parallel, on the other side of DNA it is called the lagging strands, it is made in little pieces.1849

The DNA polymerase cannot continuously make it because it is going in the opposite direction.1858

Its helicase, I will illustrate it for you on the next page.1862

That lagging strand on the other side, DNA polymerase, same type of enzyme, can attach complementary bases and fragments known as okozaki fragment.1865

It is named after the Japanese scientists who have discovered that, in the opposite direction of helicase.1875

This will make more sense on the next age, I promise.1879

Number 5, once you have copied it all, you have made a continuous strand up there,1882

fragments on this side, the lagging side, DNA polymerase 1 replaces the RNA primers with DNA nucleotides.1888

Once DNA polymerase 3 has done its job, you can get rid of the RNA primer, put DNA there.1897

Finally, you got to connect the fragments together so that it is a continuous DNA polymer.1903

DNA ligase connects the fragments together on the lagging strand.1909

What it will also do is, in these different things called replication bubbles,1912

you have thousands of these enzyme family, these enzyme units copying DNA.1918

Do not think that there is just one helicase unzipping all of your chromosomes, that would take forever.1925

Or there is just one DNA polymerase 3, there is a lot of them.1930

DNA ligase can also connect the very long leading strands to each other.1935

It is doing a lot more connecting on the lagging side.1940

Let us illustrate that on the next page.1943

Now that we have gone over the replication steps, the actual events of how DNA gets replicated,1946

I’m going to illustrate it for you.1951

This illustration is taking a very complicated process, I’m simplifying it for you.1954

As we go through, I will explain in detail what this all represents.1960

Here is a key up on top of what the different colors mean.1967

Just let you know what you are looking at here, this is just a part of DNA zoomed in1970

on a specific replication fork, within a replication bubble.1982

What you are seeing here is, if we took the double helix and unwind it, so that it looks straight,1986

here it is like this, then there is these bubbles that exist.1995

These bubbles basically mean that there are multiple sites where replication is going to occur.2001

Like I suggested earlier, you do not want there to be one set of enzymes that replicate all of DNA to genome.2010

Because sitting there are three billion base pairs in the human genome,2017

having just one helicase and one DNA polymerase, it would take so long.2022

There is a lot of different sites where these enzymes are going to be working.2027

Here is one site, this DNA has not been separated yet, but this has.2032

There is one side, there is one side that has not been separated, here is one side of DNA, there is the other side, and so on.2038

These bubbles, these replication bubbles gradually get extended and they meet to the point where replication has occurred.2046

That has been double, the new DNA is in red.2057

As time goes on, you would see black and red, red and black, all connected.2061

This, what you are looking at here is zoomed in on this specific part or this part.2069

We are looking at an edge of the reparation bubble called the replication fork.2076

I’m going to make a sequence of DNA bases here that is random, I’m just going to pick A, G, C, and T.2081

It really does not matter, you just want to make sure that the amount you have here2094

equals the amount to the bottom, and that they are complementary,2098

because complementary bases will be put together for DNA to match.2101

Here we go.2106

You can follow long, and as I’m going through this, I will go slow.2149

As I go through, you will see TTA, GCG, see if you can name the complementary base that should go there, it is good practice.2152

There you go, if you go along, check to make sure that this original DNA has its proper complements.2193

It looks like it does, we are ready to go.2199

The first step to separate this would be helicase is going from left to right.2204

Your little black arrow is saying it is going that way.2216

These bases have yet to be unzipped, the hydrogen bonds that are connecting G and C, A and T, etc, is still intact.2218

You would see 3 between here, 2 between there, and so on.2226

Helicase is going this way, it unzips pretty fast but this is how far it is gotten so far.2231

Up on top, this is going to be the leading strand.2239

On bottom, this would be the lagging strand.2250

To actually get the leading strand to be synthesized in a continuous direction,2262

you first have to put an RNA primer down, and that RNA primase will be doing that.2268

Let us say that this primer was put down right here.2273

I’m going to have to draw a U there, this was not discussed extensively, not very much at all in this lesson.2278

Uracil takes the place of thymine, of the T in RNA.2286

Blue is our RNA primer, you will see more about that in the RNA lesson, about this uracil.2291

But, there you have your complements 2 DNA in RNA form.2297

This will replace with DNA bases, remember, DNA polymerase cannot just put down bases2302

where there have not been any laid before hand.2308

DNA polymerase will add bases to this.2311

Let us say the DNA polymerase has gotten up to this point.2314

Here is DNA poly 3, it is going right my helicase.2318

Before we go any further, we got to mark the 3 prime 5 prime distinction.2325

On the leading strand, because the DNA polymerase is going from left to right,2329

we know that this side has to be 3 prime and this has to be 5 prime.2333

Remember, DNA is always read by DNA polymerase in a 3 prime to 5 prime direction.2338

It is always made in a 5 prime to 3 prime direction.2344

On the edge of this, next to DNA polymerase, we are going to have a little red 3 prime.2349

Here is that new DNA being laid down by DNA polymerase.2356

You got a C, G, there you go.2362

It is going to continue to follow continuously right behind helicase.2377

Flash forward up, a fraction of a second later, helicase will be this much further.2380

DNA polymerase will continue its attachment of new nucleotides of DNA, to what is already been laid down.2387

On this side, the lagging strand, DNA polymerase is going the opposite direction as helicase.2397

Since, it has to go in this direction, it has to wait for helicase to get so far, before it can lay down another fragment.2403

Let us say that it already laid down a fragment right here.2410

Normally, the fragments would be longer but because this is a pre concise drawing,2416

we will just say that this fragment is only 3 nucleotides long.2423

Here is what DNA polymerase has already laid down.2429

AT and T, these should match what is up here.2433

That is how you know that you are making an identical copy of your side of DNA.2439

Because we know DNA polymerase is going this direction on the lagging strand,2444

in the opposite of its helicase, here is the 5 prime, I compared it to the top, and here is the 3 prime.2448

DNA polymerase reads it from the 3 prime to the 5 prime direction always, that is why it has to go in this direction.2455

This is the previous Okazaki fragment, that term from before.2461

That is an okazaki fragment.2470

DNA polymerase is going to extend the DNA from another fragment.2472

Let us say that, we have a fragment right here that was put down.2478

Here is DNA polymerase going to the left.2489

Here is what we mean by making it in pieces, this is another okazaki fragment.2512

What DNA polymerase cannot do is, it cannot attach this fragment to that.2523

It will get all the way to this next nucleotide and then stop, dislodge and go over here,2528

and make another one as helicase move a little further.2533

It makes these little pieces.2536

Let us assume that this DNA polymerase did its job, it connected this all the way to here.2539

We should make that a T and this an A.2550

But, not connect, what first has to happen is DNA polymerase 1 will go and replace the RNA primer with new DNA.2555

This will be replaced, this will be replaced, and this will be replaced.2566

What a lovely DNA, there is that T again.2585

But, they will not be connected yet.2594

Let us assume that helicase is gone the whole route, but helicase is done with this whole replication bubble,2603

before the replacement of the primers would actually occur.2609

There is the fragments, last step is DNA ligase, this purple thing here, this purple enzyme.2618

DNA ligase binds these two together.2627

Now, they are no longer fragments.2645

Now, it does the continuous like the top.2647

You just got to use your imagination, pretend that helicase got further, all way through here.2652

This leading strand got finished, by the end you will see that the whole top side would be black and red DNA,2658

the whole bottom side would be red and black.2665

In real life, in an actual living cell, when the new DNA is made, it is not actually colored in different colors.2668

The same molecule, this newly assembled vs. your previously assembled.2675

The way that scientist proved that semi conservative replication takes place like this is2680

they did for recently tagged nucleotides that were newly put together,2684

to show that this daughter cell got that part that is old and new.2690

This little daughter cell got the other half new and half old.2695

That is the illustration of DNA replication.2699

Finally, this lesson is a little bit about junk DNA.2704

Junk, makes it sound useless, it is not useless to us.2708

According to current DNA research, only 2%, let me emphasize this, only 2% of the human genome actually codes for protein.2712

That is crazy, look at this.2723

There are 3 billion base pairs, 6 billion nucleotides in the human genome.2726

2% ends up being something like 64 million, that is still a lot of bases that is coffer for protein.2730

What does the other 98% do, why is it there?2737

A lot of them tend to be in random sequences, that do not actually coffer protein, but can be useful to us.2740

They are the numerous regions, I wrote however because I do want you think that what is the point of it being there.2746

There are numerous regions that are promoters and operators, etc.2752

Meaning, regions that do not actually coffer protein sometimes promote the activity or enhance the activity,2755

or reduce the activity of transcription in various regions near there.2761

If you mess with them, you can actually throw off proper gene expression in a cell.2766

Some of it is that, but really, I think we just barely scrape or scratch the surface rather of what is going on with their DNA.2772

There is actually recent new story about a hidden code in DNA, that scientist did not know about until recently.2785

By recently, I mean 2013.2792

Even 50 years later, 60 years later, after DNA was kind of first discovered in terms of, here is this molecule,2795

here is what we know it does, we still are coming across some novel things, regarding this miraculous code.2803

What does this junk DNA mean to us, other than just being a bunch of random sequences,2812

and promoters and operators, etc?2818

It is truly unique, meaning your junk DNA, my junk DNA, are completely different.2821

It is different from every other person that is ever lived, and ever will live, that exists now.2826

The reason it is very profound is because, think about trying to solve a crime.2831

If you got a piece of DNA from a crime scene, you know that whoever this DNA belongs to, they were here, they did is bad thing.2838

Would you want to compare the sequences for that DNA to the other sequences on people that code for hair, hair colored genes?2846

No, because there are millions or billions of people on earth with that same trait.2857

You do not want to compare those things.2863

You want compare the regions that are truly unique in that person's DNA.2864

Junk DNA has these random sequences and the reason why your sequence is a random, they came from your parents randomness.2868

The combination of your parent’s randomness equals your randomness.2877

No one else on earth has junk DNA sequences like yours.2881

You can use them to do what is called DNA fingerprinting.2885

When I write here that it can be used for forensic science, paternal test, etc., that is known as DNA fingerprinting.2889

It is like your DNA is a unique genetic fingerprint, it is a pretty good analogy because no one else on earth has your junk DNA.2900

But, plenty of people on earth have your DNA associated with metabolism or associated with how tall you are, or your eye color.2911

Those are the parts that you do not want to compare.2919

Forensic science like catching a criminal, comparing sequences in people around the world2921

to try to find interesting patterns of who came from who, and migration patterns,2928

very interesting in figuring out the history of our human genome.2934

Paternal tests, you do not want to compare the parts of your genome that have to do with hair,2939

because that will not prove that someone is the father or mother, or not, because plenty of people have that same hair color.2946

But comparing the junk DNA is foolproof that someone is or is not the parent.2952

DNA technology uses these sequences, these junk DNA sequences.2959

Gel electrophoresis, I want to briefly explain.2963

There is a lot more on that in the genetics lesson, part 2, regarding genetic engineering.2966

But basically, what gel electrophoresis does, it takes these junk DNA segments,2973

uses restriction enzymes which cut up DNA at very specific parts.2977

For instance, the restriction enzyme will target any spot where you see those 5 bases and their exact sequence.2984

It will cut the DNA right there.2991

In your junk DNA, the precise parts where you see that are very different2994

from the precise parts where you see those gene sequences in mine, or rather base sequences.2999

You will get DNA cut into different sizes, different lengths, based on the unique individual.3005

You can load those DNA sequences all cut up into these little wells.3011

This is what is called gel electrophoresis piece, this is a gel that you lay down with electrodes in a chamber.3017

This side is negative, this side is positively charged, you turn on the current.3023

Since DNA is negatively charged, the DNA migrates, you get different bonding patterns3027

based on how long or how small the DNA segments are.3033

I just drew 4 unique people, what I mean is, these sequences up here are very long, they actually drag in the gel as it got electricity pulls them, so it do not make it as far.3042

These sequences down here, very short DNA sequences that make this little pattern in the gel.3053

If two people are identical, if someone is identical to a sample, and they would actually have more patterns than this.3058

I will just give you a quick example.3071

But, you can see that 3 and well 4, it is the same individual.3073

It is like a 1 in 7 billion chance that this is going to be wrong because3079

there is over 7 billion people on earth, 7 billion unique sets of junk DNA.3083

That is one application of using these, apparently, random sequences of DNA.3090

Apparently, use these genes for something that is very useful in our daily life.3095

Thank you for watching www.educator.com.3101

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