Answer to Question #171260 in Biochemistry for Kim

Question

1. At eukaryotic origins of replication, helicase cannot be activated until the polymerase is also positioned on the DNA. Explain what would happen if the helicase became active in the absence of DNA polymerase.

2. RNA synthesis is much less accurate than DNA synthesis. Why does this not harm the cell?

3. What is the role of folate in the synthesis of nitrogenous bases of purines?

Answer 1

Ans1: The function of helicase is to break the hydrogen bonds between the two strands of the DNA and in this way it seperates two strands of the DNA.

The function of DNA polymerase is to make copies of DNA strands that are seperated by the helicase enzyme. If helicase is active but DNA polymerase is absent then DNA strands will remain seperated and new DNA strands will not be synthesized.

Ans2: Many molecules of RNA strands are synthesized from the perticular gene. So any error will affect only one molecule of RNA. Errors in transcription affect only protein and the genome will not be affected.

Ans3: Folate is involved in the synthesis inosine mono phosphate and this is the precursor for the synthesis of GMP and AMP.