Question

11. Several enzymes and proteins participate in DNA replication. Answer the fill in the blan below bonds unwinds DNA by breaking the a. The enzyme between the nitrogenous bases bind to single-stranded DNA to stabilize it and to prevent it from reannealing to the other DNA strand. makes DNA This enzyme adds nuceotides to the end of a nucleic acid strands; therefore, it makes DNA in the to direction . DNA Polymerase cannot put two nucleotides together, instead, it adds nucleotides to a nucles acid strand; therefore, the enzyme puts down an primer to begin replication e. At the end of replication the enzyme covalently links Okazaki fragments together. 12. DNA replication is described as semi-conservative. What does that mean? 13. Look at the image below. The black lines are the template DNA strands. The enzyme helicase is shown by an arrow head indicating the direction helicase is unwinding the DNA (the direction the replication fork is moving). The blue lines indicate newly synthesized strands. Is strand "a" the leading strand or the lagging strand? helicase

Answer 1

a) the enzyme helicase unwinds DNA by breaking the hydrogen bonds between the nitrogenous bases

b) Single-strand binding proteins bind to the single-stranded DNA to stabilize and prevent it from reannealing to the other DNA strand.

c) DNA polymerase makes DNA. The enzyme adds nucleotides to the 3` end of the nucleic acid strands. It makes DNA in the 5` to 3` direction.

d) The DNA polymerase cannot put two nucleotides together, instead, it adds nucleotides to a nucleic acid strand, therefore, enzyme primase puts down an RNA primer to begin replication.

e) at the end of DNA replication enzyme DNA ligase links Okazaki fragments together.