/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 32 During mismatch repair, why is i... [FREE SOLUTION] | 91影视

91影视

Log out

Learning Materials

Features

Discover

Chapter 19: Problem 32

During mismatch repair, why is it necessary to distinguish between the template strand and the newly made daughter strand? How is this accomplished?

Short Answer

Expert verified
Distinguishing between the template and the daughter strand during mismatch repair is crucial in maintaining the accuracy of DNA replication as it allows the system to correct errors in the newly synthesized strand based on the correct sequence in the template strand. This is accomplished by recognizing the methylation pattern of the template strand which remains fully methylated after DNA replication, while the newly synthesized daughter strand is not yet methylated.

Step by step solution

01

Understand the Necessity for Distinguishing Strands

Mismatch repair is a highly important process for maintaining the accuracy of DNA replication. For the system to function properly, it has to identify which strand is the original template and which one is newly synthesized. This is necessary because the system corrects errors by replacing erroneous bases in the newly synthesized strand, leaving the original template strand intact. If the mismatch repair system could not distinguish the two strands, errors could be introduced rather than corrected.
02

Define the Mechanism of Distinguishing Strands

The mechanism for distinguishing the original template from the daughter strand is based on methylation. In E.coli, after DNA replication, the template strand is fully methylated while the newly synthesized daughter strand is non-methylated. So, the repair system recognizes the methylation pattern of the parental strand and introduces corrections on the newly made, not-yet-methylated daughter strand.
03

Describe the Process of Methyl-directed Mismatch Repair

Once the mismatched bases are identified between the originally methylated template and the not-yet-methylated daughter strand, the repair system excises the segment of the daughter strand containing the wrong base. Then, DNA polymerase fills in the gap by synthesizing new DNA using the original template strand as a guide. DNA ligase finally seals the nick.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91影视!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

A segment of DNA has the folloving sequence: TTGGATGCTG AACCTACGAC A. What would the sequence be immediately after reaction with nitrous acid? Let the letters \(\mathrm{H}\) represent hypoxanthine and U represent uracil. B. Let's suppose this DNA was reacted with nitrous acid. The nitrous acid was then removed, and the DNA was replicated for two generations. What would be the sequences of the DNA products after the DNA had replicated tao times? (Note: Hypoxanthine pairs with cytasine.) Your answer should contain the secquences of four double helices.

Make a drawing that shoss how alkylating agents aller the struc ture of DNA, and explain the process.

Give an example of a mulagen that can change cytosine to uracil. Which DNA repair system(s) would be able to repair this defect?

What is the underlying genetic defect that causes seroderma pig. mentosum? How can the symptoms of this disease be explained by the genetic defect?

Are mutations random events? Explain your answer.
See all solutions

Recommended explanations on Biology Textbooks

Organ Systems

Read Explanation

Biology Experiments

Read Explanation

Biological Processes

Read Explanation

Responding to Change

Read Explanation

Ecology

Read Explanation

Substance Exchange

Read Explanation
View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.