DNA replication is a highly coordinated process that involves a number of different enzymes. It is essential that the process is done correctly; otherwise, mutations will arise.DNA Replication by Madprime (CC0)Which of the following statements correctly pairs the enzyme involved in DNA replication with its function?Elimination ToolSelect one answerATopoisomerase: places down primers.BRNA polymerase: creates the new strands of DNA.CHelicase: breaks bonds between nucleotides.DPrimase: releases tension in the sugar-phosphate backbone.
Question
DNA replication is a highly coordinated process that involves a number of different enzymes. It is essential that the process is done correctly; otherwise, mutations will arise.DNA Replication by Madprime (CC0)Which of the following statements correctly pairs the enzyme involved in DNA replication with its function?Elimination ToolSelect one answerATopoisomerase: places down primers.BRNA polymerase: creates the new strands of DNA.CHelicase: breaks bonds between nucleotides.DPrimase: releases tension in the sugar-phosphate backbone.
Solution
The correct answer is C. Helicase: breaks bonds between nucleotides.
Here's why:
A. Topoisomerase: This enzyme does not place down primers. Instead, it helps to relieve the tension in the DNA molecule that is caused by the unwinding of the double helix.
B. RNA polymerase: This enzyme is involved in transcription, not DNA replication. It synthesizes RNA from a DNA template.
C. Helicase: This is the correct answer. Helicase is the enzyme that unwinds the DNA double helix by breaking the hydrogen bonds between the nucleotide pairs. This allows the two single strands of DNA to serve as templates for replication.
D. Primase: This enzyme does not release tension in the sugar-phosphate backbone. Instead, it synthesizes a short RNA segment that serves as a primer for DNA replication.
Similar Questions
What is the function of DNA polymerase during DNA replication?
Explain how DNA replication works using steps
DNA polymerization is one of the most conserved mechanisms of genome replication. Synthesis of a complete DNA strand requires a template, primers, a polymerase enzyme, and sufficient deoxyribonucleotide triphosphates (dNTPs). The DNA polymerase enzyme binds consecutive base pairs on the template strand and extends the double helix by adding dNTPs to the primer. The amino acid residues in the active site of DNA polymerase form hydrogen bonds with Watson-Crick donors and acceptors on incoming DNA nucleotides to facilitate base pairing.The formation of the DNA double helix creates opposing changes in entropy and enthalpy. Favorable bonding interactions via hydrogen bonds during Watson-Crick base pairing results in negative enthalpy, and restricted rotation and flexibility of the DNA backbone generates negative entropy. Scientists hypothesize that hydrogen bonding between bases not only stabilizes the double helix but is also crucial for selective and efficient replication.Analogs that are similar in size and shape to naturally occurring bases can be used to determine the influence of hydrogen bonding on base pair selectivity. To mimic the structure of deoxythymidine triphosphate (dTTP), researchers synthesized dNTP derivatives of difluorotoluene (dFTP). dFTP is a nonpolar analog of dTTP that lacks Watson-Crick hydrogen bonding. Klenow fragment polymerase (KF), which has 3′-5′ but not 5′-3′ exonuclease activity, was incubated with a mixture of DNA template, primers, and dNTPs, including dFTP. The efficiency of dFTP and natural dTTP nucleotide incorporation into a growing primer strand by KF is shown in Figure 1.Figure 1 Template-specific selection of dFTP and dTTP by the KF enzymeAdapted from Moran S, Ren RX, Kool ET. A thymidine triphosphate shape analog lacking Watson-Crick pairing ability is replicated with high sequence selectivity. Proc Natl Acad Sci USA. 1997;94(20):10506-11. Question 44The Klenow fragment used in the experiment would be able to perform which of the following repair processes?A.Correction of mismatched nucleotides in the middle of a completed strandB.Replacement of nucleotides at the 3′ end of the growing strandC.Excision of thymine dimers at the 5′ end of the growing strandD.Removal of damaged bases from the middle of the template strand
The enzyme DNA covalently links nucleotides to synthesize new DNA strands together during DNA replication.
DNA replication: steps
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