The structure of DNA and RNA are very similar, although DNA is a double helix and RNA is single stranded. The monomers that compose them are called nucleotides and contain a sugar (ribose for RNA, deoxyribose for DNA), a nitrogenous base, and a phosphate group. There are five nitrogenous bases, but uracil is only found in RNA and thymine (T) is only in DNA. The other three are adenine (A), guanine (G), and cytosine (C). DNA is replicated semiconservatively. The double helix unwinds and each half is used as a template for DNA polymerase to assemble the complementary proteins (C pairs with G and A pairs with T). The resulting strands are proofread and repaired. Telomeres sit at the 5 end of the chain and do not code for proteins.
replication is semiconservative. Each strand is used as a template
for the synthesis of a complementary strand.
replication begins at an origin of replication. DNA
Helicase unwinds the double helix, creating a replication bubble.
binding proteins stabilize the DNA strands and hold them apart.
cut, unwind and religate, the DNA ahead of the replication fork in
order to relieve the tension caused by unwinding the double helix.
polymerases synthesize the complementary strand of DNA in the 5'
to 3' direction and require a primer. An RNA primer is synthesized
is synthesized in one long strand for the leading strand on the
template DNA. For the lagging strand, DNA is synthesized in short
segments called Okazaki fragments.
polymerase possesses a proofreading function. If an incorrect
nucleotide is added to the growing strand of DNA, it is removed and
and damaged DNA are also corrected through mismatch repair.
are repeating nucleotide sequences on the ends of DNA molecules.
These segments become shorter with each round of DNA replication.
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.