Problem 1
Define template and primer as they relate to DNA synthesis.
Problem 2
Explain why DNA synthesis depends on RNA synthesis.
Problem 3
What is an Okazaki fragment?
Problem 4
Distinguish between the leading and the lagging strands in DNA synthesis.
Problem 5
Match each term with its description. (a) DNA polymerase 1\. Unwinds the double helix \(x^{3}\) 2\. Crucial for proofreading (b) Template 3\. Uses ATP to join DNA (c) Primer (d) Helicase fragments 4\. Determines the sequence (e) Topoisomerase (f) Exonuclease (g) Primase 5\. Faithfully replicates the (h) Okazaki fragment 6\. Synthesizes a segment of (i) DNA ligase RNA 7\. Found on the lagging (j) Telomerase 8\. The initial segment of a polymer that will be extended 9\. Prevents the disappearance of the lagging strand 10\. Relaxes or introduces supercoils
Problem 6
Explain, on the basis of nucleotide structure, why DNA synthesis proceeds in the \(5^{\prime}\) -to-3 direction.
Problem 7
For long double-stranded DNA molecules, the rate of spontaneous strand separation is negligibly low under physiological conditions despite the fact that only weak reversible bonds hold the strands together. Explain.
Problem 9
Why would replication come to a halt in the absence of topoisomerase II?
Problem 10
Telomerase is not active in most human cells. Some cancer biologists have suggested that the activation of the telomerase gene would be a requirement for a cell to become cancerous. Explain.
Problem 11
With the assumption that the energy required to break an average base pair in DNA is \(10 \mathrm{kJ}\) \(\mathrm{mol}^{-1}\left(2.4 \mathrm{kcal} \mathrm{mol}^{-1}\right),\) estimate the maximum number of base pairs that could be broken per ATP hydrolyzed by a helicase operating under standard conditions.
