AP BIOLOGY

Detailed explanation-1: -DNA replication takes place at a Y-shaped structure called a replication fork. A self-correcting DNA polymerase enzyme catalyzes nucleotide polymerization in a 5′-to-3′ direction, copying a DNA template strand with remarkable fidelity.

Detailed explanation-2: -To synthesize DNA, the double-stranded DNA is unwound by DNA helicases ahead of polymerases, forming a replication fork containing two single-stranded templates. Replication processes permit the copying of a single DNA double helix into two DNA helices, which are divided into the daughter cells at mitosis.

Detailed explanation-3: -Certain proteins bind to the origin of replication while an enzyme called helicase unwinds and opens up the DNA helix. As the DNA opens up, Y-shaped structures called replication forks are formed (Figure 3).

Detailed explanation-4: -During DNA replication, DNA helicases unwind DNA at positions called origins where synthesis will be initiated. DNA helicase continues to unwind the DNA forming a structure called the replication fork, which is named for the forked appearance of the two strands of DNA as they are unzipped apart.

Detailed explanation-5: -DNA helicase is needed in order to open the DNA to expose the nucleotide bases that are used as the template for replicating the DNA. The area of the DNA that is opened by DNA helicase is known as the replication fork because it looks very similar to a fork in the road.