AP BIOLOGY

Detailed explanation-1: -This means DNA replication must begin by separating the two strands of the original DNA molecule. This is accomplished by two enzymes: topoisomerase, which untwists the helical molecule, and helicase, the “unzipper” that breaks the hydrogen bonds and separates the two strands.

Detailed explanation-2: -The first step in DNA replication is to ‘unzip’ the double helix structure of the DNA? molecule. This is carried out by an enzyme? called helicase which breaks the hydrogen bonds? holding the complementary? bases? of DNA together (A with T, C with G).

Detailed explanation-3: -With an eye toward understanding DNA replication, Cornell researchers have learned how a helicase enzyme works to actually unzip the two strands of DNA. The results are published in the journal Nature. At the heart of many metabolic processes, including DNA replication, are enzymes called helicases.

Detailed explanation-4: -The enzyme helicase unzips the two strands of the double helix. Once unzipped, single stranded binding (SSB) proteins stabilize the newly single strands. The enzyme DNA gyrase ensure the double stranded areas beyond the replication fork do not supercoil onto one another.

Detailed explanation-5: -Abstract. Helicases are essential enzymes involved in all aspects of nucleic acid metabolism including DNA replication, repair, recombination, transcription, ribosome biogenesis and RNA processing, translation, and decay.