Question

topoisomerase and helicase
dna replication is carried out by a series of enzymes all working together. topoisomerase, one of these enzymes, is involved in unwinding the dna strand. as replication occurs, the dna strand becomes overly twisted and can snap. topoisomerase cuts the strand of dna, allowing it to untwist. then it reattaches the dna strands together where it was cut. helicase, another enzyme, breaks the hydrogen bonds that hold bases together, allowing other enzymes to add complementary nucleotides. single - strand binding proteins (ssbs) keep the strands separated.

1. □ unwinds dna
2. helicase separates the nitrogenous bases

by breaking the □ bonds.

1. ssb proteins keep the two strands □

Explanation:

Question 14

From the text, Topoisomerase is involved in unwinding the DNA strand. So the enzyme that unwinds DNA is Topoisomerase.

The text states that Helicase breaks the hydrogen bonds that hold bases together. So the bonds broken by Helicase are hydrogen bonds.

The text says Single - Strand Binding Proteins (SSBs) keep the strands separated. So SSB Proteins keep the two strands separated.

Answer:

Topoisomerase

Question 15