AP BIOLOGY

Detailed explanation-1: -Helicases are enzymes that separate the nucleic acid strands for replication. Topoisomerases are enzymes that relax the supercoiling in DNA strands. It utilises energy from the hydrolysis of nucleoside triphosphates to translocate through the DNA strands.

Detailed explanation-2: -Topoisomerases are nuclear enzymes that play essential roles in DNA replication, transcription, chromosome segregation, and recombination. All cells have two major forms of topoisomerases: type I, which makes single-stranded cuts in DNA, and type II enzymes, which cut and pass double-stranded DNA.

Detailed explanation-3: -Key enzyme involved in DNA replication, it is responsible for ‘unzipping’ the double helix structure by breaking the hydrogen bonds between bases on opposite strands of the DNA molecule.

Detailed explanation-4: - DNA topoisomerases are ubiquitous enzymes found in all cell types from viruses to man. These enzymes act to regulate DNA supercoiling by catalysing the winding and unwinding of DNA strands.