Genetic information is stored in DNA. An RNA transcript can be made and transported into the cytoplasm, where it translated into proteins. RNA comes in three forms: messenger (mRNA), ribosomal (rRNA), and transfer (tRNA). Transcription takes place in three parts: initiation, elongation, and termination. Translation builds an amino acid sequence based on the genetic code. Start and end points are indicated using codons. Silent mutations can occur where the same proteins are translated even though the genetic code has changed as redundancy is built into the genetic code. The second type is missense mutation, where a different amino acid will be added to a protein chain based on the genetic mutation. Nonsense mutations form a stop codon. Natural errors, chemicals, excessive sunlight, and radiation can all cause mutations.
is initiated when RNA polymerase and transcription factors bind to
the promoter region of a gene. The promoter frequently includes the
nucleotide sequence TATA and is known as a TATA box.
transcription, the pre-mRNA undergoes processing to form mRNA.
Introns are removed through splicing and a 5' cap and a poly A
tail are added to the mRNA.
mRNA is transported out of the nucleus to the cytoplasm where
translation takes place.
triplets, called codons, signify particular amino acids.
three phases of translation are also initiation, elongation and
begins at the start codon AUG, which is also the codon for
methionine. Transfer RNA (tRNA) delivers the amino acids to the
ribosome to be added to the growing polypeptide chain.
is terminated when the ribosome encounters a stop codon.
are changes in the DNA sequence. A change in a single base pair is a
point mutations. Types of mutations include silent,missense and nonsense mutations.
and deletions result in base pairs being added or eliminated from
the DNA sequence. This results in a frameshift mutation.
Transcription and Translation
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.
The book and CD package include two full length practice exams that are presented with all questions answered and explained. The author also presents detailed reviews of all test topics and includes multiple-choice and free-response questions with answers at the end of each topic's chapter.
This book includes a review of the AP Biology exam format and scoring, proven strategies for answering multiple-choice questions, and hints for tackling the essay questions. The practice tests include answers and explanations and there is also proven test-taking strategies for both the multiple choice and essay parts.