Table of contents

1. Introduction to Genetics51m
2. Mendel's Laws of Inheritance3h 37m
3. Extensions to Mendelian Inheritance2h 41m
4. Genetic Mapping and Linkage2h 28m
5. Genetics of Bacteria and Viruses1h 21m
6. Chromosomal Variation1h 48m
7. DNA and Chromosome Structure56m
8. DNA Replication1h 10m
9. Mitosis and Meiosis1h 34m
10. Transcription1h 0m
11. Translation58m
12. Gene Regulation in Prokaryotes1h 19m
13. Gene Regulation in Eukaryotes44m
14. Genetic Control of Development44m
15. Genomes and Genomics1h 50m
16. Transposable Elements47m
17. Mutation, Repair, and Recombination1h 6m
18. Molecular Genetic Tools19m
- Genetic Cloning
  9m
- Methods for Analyzing DNA
  9m
19. Cancer Genetics29m
- Overview of Cancer
  21m
- Cancer Mutations
  7m
20. Quantitative Genetics1h 26m
21. Population Genetics50m
- Hardy Weinberg
  19m
- Allelic Frequency Changes
  31m
22. Evolutionary Genetics29m

7. DNA and Chromosome Structure

DNA Structure

Genetics

7. DNA and Chromosome Structure

DNA Structure

Previous problemNext problem

1:47 minutes

Problem 7

Textbook Question

For the following fragment of DNA, determine the number of hydrogen bonds and the number of phosphodiester bonds present:
5'-ACGTAGAGTGCTC-3'
3'-TGCATCTCACGAG-5'

Verified step by step guidance

Step 1: Understand the structure of DNA. DNA is composed of two strands that are complementary and antiparallel. Each base pair is connected by hydrogen bonds, and the backbone of each strand is connected by phosphodiester bonds.

Step 2: Count the hydrogen bonds between the base pairs. Adenine (A) pairs with Thymine (T) via 2 hydrogen bonds, and Cytosine (C) pairs with Guanine (G) via 3 hydrogen bonds. Analyze the sequence to determine the number of each base pair and calculate the total hydrogen bonds.

Step 3: Count the phosphodiester bonds in the DNA backbone. Phosphodiester bonds connect the sugar-phosphate backbone of each strand. For a single strand of DNA, the number of phosphodiester bonds is one less than the number of nucleotides. Count the nucleotides in one strand and subtract 1 to find the number of phosphodiester bonds in that strand.

Step 4: Multiply the phosphodiester bond count by 2 since there are two strands in the DNA molecule. This gives the total number of phosphodiester bonds in the double-stranded DNA.

Step 5: Combine the results from steps 2 and 4 to summarize the total number of hydrogen bonds and phosphodiester bonds present in the given DNA fragment.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above

Video duration:

Play a video:

Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Hydrogen Bonds

Hydrogen bonds are weak interactions that occur between complementary nitrogenous bases in DNA. In the double helix structure, adenine (A) pairs with thymine (T) through two hydrogen bonds, while cytosine (C) pairs with guanine (G) through three hydrogen bonds. Understanding the number of hydrogen bonds is crucial for determining the stability and structure of the DNA molecule.

Phosphodiester Bonds

Phosphodiester bonds are covalent linkages that connect the sugar and phosphate groups of adjacent nucleotides in a DNA strand. These bonds form the backbone of the DNA molecule, providing structural integrity. Each DNA strand has a continuous chain of phosphodiester bonds, and recognizing their presence is essential for understanding the overall structure and function of DNA.

Complementary Base Pairing

Complementary base pairing refers to the specific pairing of nitrogenous bases in DNA, where A pairs with T and C pairs with G. This principle is fundamental to DNA replication and transcription, as it ensures accurate copying of genetic information. Identifying the base pairs in the given DNA sequence is necessary to calculate the number of hydrogen bonds formed between the strands.

Watch next

Master DNA Structure with a bite sized video explanation from Kylia

Start learning

Related Videos

Related Practice

Textbook Question

One strand of a fragment of duplex DNA has the sequence 5'-ATCGACCTGATC-3'.

Is the bond in part (b) a covalent or a noncovalent bond?

340

views

Textbook Question

One strand of a fragment of duplex DNA has the sequence 5'-ATCGACCTGATC-3'.

What is the name of the bond that joins one nucleotide to another in the DNA strand?

548

views

Textbook Question

One strand of a fragment of duplex DNA has the sequence 5'-ATCGACCTGATC-3'.

What is the sequence of the other strand in the duplex?

554

views

Textbook Question

The principles of complementary base pairing and antiparallel polarity of nucleic acid strands in a duplex are universal for the formation of nucleic acid duplexes. What is the chemical basis for this universality?

492

views

Textbook Question

The following figure (Figure 1.6) presents simplified depictions of nucleotides containing deoxyribose, a nucleotide base, and a phosphate group. Use this simplified method of representation to illustrate the sequence 3'-AGTCGAT-5' and its complementary partner in a DNA duplex.

How many hydrogen bonds are present in this DNA duplex?

417

views

Textbook Question

How many phosphodiester bonds are present in this DNA duplex?

353

views

Textbook Question

What kind of bonds join the C in one strand to the G in the complementary strand?

411

views

Textbook Question