Biochemistry: The Molecular Basis of Life
Biochemistry: The Molecular Basis of Life
6th Edition
ISBN: 9780190209896
Author: Trudy McKee, James R. McKee
Publisher: Oxford University Press
bartleby

Videos

Question
Book Icon
Chapter 17, Problem 1Q
Summary Introduction

To review:

The deoxyribonucleic acid (DNA) molecule that denatures first on heating from the given two deoxyribonucleic acid (DNA) molecules, and the reason behind its early denaturation.

5’-GCATTTCGGCGCGTTA-3’3’-CGTAAAGCCGCGCAAT-5’       5’-ATTGCGCTTATATGCT-3’3’-TAACGCGAATATACGA-5’

Introduction:

The deoxyribonucleic acid (DNA) molecule has a double helical structure that is stabilized by different forces. These forces include hydrophobic interactions, hydrogen bonds, base stacking, and electrostatic interactions.

Expert Solution & Answer
Check Mark

Explanation of Solution

The second DNAmolecule denatures first because it has smaller number of guanine–cytosine (GC) base pairs, and thus less amount of GCcontent (37.64%).The GC content is measured by dividing the number of cytosine and guanine nucleotides present in deoxyribonucleic acid sequence by the total number of base pairs in the sequence.

The base stacking interactions in the second molecule are less than the interactions in the first molecule. The GC content for the first molecule is higher (56.25%), and the base stacking is stronger as well. A lower amount of heat energy is required to break down the hydrogen bonds and stacking interactions, in the second molecule, and it denatures earlier than the other DNAmolecule.

The base pairs in the deoxyribonucleic acid (DNA) molecule are joined by hydrogen bonds. There are 3 hydrogen bonds between guanine and cytosine while only 2 hydrogen bonds are present between adenine and thymine. The triple bond between guanine-cytosine is stronger than the double bond between adenine and thymine. More energy is required to denature the DNA molecule since ithas more guanine–cytosine base pairs.

Conclusion

It can be concluded that the second deoxyribonucleic acid molecule denatures first on heating because of comparatively weaker base stacking interactions and lower GCcontent.

Want to see more full solutions like this?

Subscribe now to access step-by-step solutions to millions of textbook problems written by subject matter experts!
Students have asked these similar questions
When DNA is heated, it denatures; that is, the strands separate because hydrogen bonds are broken and some base-stacking and hydrophobic interactions are disrupted. The higher the temperature, the larger the number of hydrogen bonds that are broken. After reviewing DNA base pair structure, determine which of the following molecules will denature first as the temperature is raised. Explain your reasoning. a. 5′-GCATTTCGGCGCGTTA-3′ 3′-CGTAAAGCCGCGCAAT-5′ b. 5′-ATTGCGCTTATATGCT-3′ 3′-TAACGCGAATATACGA-5′
Explain how DNA-binding proteins can make sequence-specific contacts to a double-stranded DNA molecule without breaking the hydrogen bonds that hold the bases together. indicate how, through such contacts, a protein can distinguish a T-A from a C-G pair. indicate the parts of the nucleotide base pairs that could form noncovalent interactions— hydrogen bonds, electrostatic attractions, or hydrophobic interactions -with a DNA-binding protein.
The two sides of the DNA double helix are connected by pairs of bases (adenine, thymine, cytosine, and guanine). Because of the geometric shape of these molecules, adenine bonds with thymine and cytosine bonds with guanine. The figure (Figure 1) shows the thymine-adenine bond. Each charge shown is ±e, and the H−N distance is 0.110 nm . Calculate the net force that thymine exerts on adenine. To keep the calculations fairly simple, yet reasonable, consider only the forces due to the O−H−N and the N−H−N combinations, assuming that these two combinations are parallel to each other. Remember, however, that in the O−H−N set, the O− exerts a force on both the H+ and the N−, and likewise along the N−H−N set. Express your answer in newtons.   Is the net force attractive or repulsive?

Chapter 17 Solutions

Biochemistry: The Molecular Basis of Life

Knowledge Booster
Background pattern image
Biochemistry
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, biochemistry and related others by exploring similar questions and additional content below.
Similar questions
SEE MORE QUESTIONS
Recommended textbooks for you
Text book image
Human Heredity: Principles and Issues (MindTap Co...
Biology
ISBN:9781305251052
Author:Michael Cummings
Publisher:Cengage Learning
QCE Biology: Introduction to Gene Expression; Author: Atomi;https://www.youtube.com/watch?v=a7hydUtCIJk;License: Standard YouTube License, CC-BY