AP BIOLOGY

Detailed explanation-1: -The initiation of DNA replication occurs in two steps. First, a so-called initiator protein unwinds a short stretch of the DNA double helix. Then, a protein known as helicase attaches to and breaks apart the hydrogen bonds between the bases on the DNA strands, thereby pulling apart the two strands.

Detailed explanation-2: -DNA helicases are essential during DNA replication because they separate double-stranded DNA into single strands allowing each strand to be copied. During DNA replication, DNA helicases unwind DNA at positions called origins where synthesis will be initiated.

Detailed explanation-3: -The separated place of DNA strand is called replication fork. During DNA replication separation of the two DNA strands that make up the helix that is to be copied. DNA Helicase enzyme untwists the helix at locations called replication origins. The replication origin forms a ‘Y’ shape, and is called a replication fork.

Detailed explanation-4: -In order to start DNA replication, helicase needs to unwind the molecule and break apart the hydrogen bonds holding together complementary nitrogenous bases. This causes the two strands of DNA to separate.

Detailed explanation-5: -DNA replication occurs through the help of several enzymes. These enzymes “unzip” DNA molecules by breaking the hydrogen bonds that hold the two strands together.