Let’s dive into the answers and explanations. Question 1: Draw and label a nucleotide. What are the three components?

| Enzyme | Function | |--------|----------| | | Unwinds and separates the double helix by breaking hydrogen bonds. | | DNA Polymerase III | Synthesizes new DNA strands by adding nucleotides to the 3’ end; also has 3’→5’ proofreading ability. | | Primase | Synthesizes a short RNA primer to provide a 3’-OH group for DNA polymerase to begin adding nucleotides. | | Ligase | Seals nicks (joins Okazaki fragments) on the lagging strand by forming phosphodiester bonds. | | Topoisomerase | Relieves supercoiling ahead of the replication fork to prevent DNA breakage. |

The purine-to-pyrimidine ratio is always 1:1 in a double-stranded DNA molecule (Chargaff’s rule). Part 2: DNA Function (Replication & Central Dogma) Question 5: Explain the role of the following enzymes in DNA replication:

Understanding DNA structure and function is the cornerstone of molecular biology and a critical topic for the AP Biology exam. This post provides a comprehensive answer key for a typical AP Biology worksheet on DNA, including detailed explanations to help you understand why each answer is correct.

Compare and contrast the leading strand and the lagging strand .

Hydrogen bonds hold the two strands together. Specifically, two hydrogen bonds form between A and T, and three hydrogen bonds form between G and C.

What type of bond holds the two strands of DNA together? Why is this bond important for DNA replication?