AP BIOLOGY

Detailed explanation-1: -Topoisomerases (red) reduce torsional strain caused by the unwinding of the DNA double helix; DNA helicase (yellow) breaks hydrogen bonds between complementary base-pairs; single-strand binding proteins (SSBs) stabilize the separated strands and prevent them from rejoining.

Detailed explanation-2: -DNA Helicases-These proteins bind to the double stranded DNA and stimulate the separation of the two strands. DNA single-stranded binding proteins-These proteins bind to the DNA as a tetramer and stabilize the single-stranded structure that is generated by the action of the helicases.

Detailed explanation-3: -Additional replication proteins are needed to help in opening the double helix and thus provide the appropriate single-stranded DNA template for the DNA polymerase to copy. Two types of protein contribute to this process-DNA helicases and single-strand DNA-binding proteins.

Detailed explanation-4: -Explanation: Helicase is the protein resposible for unwinding the DNA double-helix. Single-strand binding proteins attach to the freshly unwound strands of DNA and ensure that the strands do not re-anneal.

Detailed explanation-5: -SSBs (and RPAs) stabilize the separated strands through rapid binding that ensures complete coating of the ssDNA as it emerges from the helicase.