Table of contents

1. Introduction to Anatomy & Physiology5h 43m
2. Cell Chemistry & Cell Components12h 36m
3. Energy & Cell Processes10h 6m
4. Tissues & Histology10h 3m
5. Integumentary System2h 20m
6. Bones & Skeletal Tissue2h 16m
7. The Skeletal System2h 35m
8. Joints2h 17m
9. Muscle Tissue2h 33m
10. Muscles1h 11m
11. Nervous Tissue and Nervous System1h 35m
12. The Central Nervous System1h 6m
- Introduction to the Central Nervous System
  18m
- The Cerebrum
  48m
13. The Peripheral Nervous System1h 26m
14. The Autonomic Nervous System1h 38m
15. The Special Senses2h 41m
16. The Endocrine System2h 48m
17. The Blood3h 22m
18. The Heart3h 42m
19. The Blood Vessels3h 35m
20. The Lymphatic System3h 16m
21. The Immune System14h 37m
22. The Respiratory System3h 20m
23. The Digestive System2h 5m
24. Metabolism and Nutrition4h 0m
25. The Urinary System2h 39m
26. Fluid and Electrolyte Balance, Acid Base Balance37m
27. The Reproductive System2h 5m
28. Human Development1h 21m
29. Heredity3h 32m

2. Cell Chemistry & Cell Components

Nucleic Acids

Anatomy & Physiology

2. Cell Chemistry & Cell Components

Nucleic Acids

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Problem 5

Textbook Question

Enzymes that break down DNA catalyze the hydrolysis of the covalent bonds that join nucleotides together. What would happen to DNA molecules treated with these enzymes?a. The two strands of the double helix would separate.b. The phosphodiester linkages of the polynucleotide backbone would be broken.c. The pyrimidines would be separated from the deoxyribose sugars.d. All bases would be separated from the deoxyribose sugars.

Verified step by step guidance

Understand the role of enzymes that break down DNA: These enzymes, known as DNases, specifically catalyze the hydrolysis of the covalent bonds in DNA.

Identify the type of bonds targeted by these enzymes: DNases hydrolyze the phosphodiester bonds within the DNA molecule.

Analyze the structure of DNA: DNA is composed of a double helix structure with two strands linked by hydrogen bonds and each strand consisting of a sugar-phosphate backbone and nitrogenous bases attached to the sugar.

Determine the effect of breaking phosphodiester bonds: Hydrolyzing these bonds affects the integrity of the sugar-phosphate backbone, which holds the nucleotides together in a single strand.

Conclude the immediate structural change in DNA when treated with these enzymes: The breaking of phosphodiester bonds would lead to the fragmentation of the DNA strands into smaller pieces or individual nucleotides, but would not directly affect the hydrogen bonds between the strands or the attachment of bases to the sugars.

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Key Concepts

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

Enzyme Function

Enzymes are biological catalysts that speed up chemical reactions by lowering the activation energy required. In the context of DNA, specific enzymes, such as nucleases, facilitate the breakdown of DNA by catalyzing the hydrolysis of covalent bonds between nucleotides, leading to the degradation of the DNA structure.

Covalent Bonds in DNA

DNA is composed of nucleotides linked together by covalent bonds known as phosphodiester linkages. These bonds connect the phosphate group of one nucleotide to the sugar of the next, forming the backbone of the DNA strand. Hydrolysis of these bonds results in the fragmentation of the DNA molecule.

Double Helix Structure

The double helix structure of DNA consists of two strands that are complementary and anti-parallel. The stability of this structure relies on both hydrogen bonds between the nitrogenous bases and the covalent phosphodiester linkages in the backbone. When enzymes break these linkages, the strands can separate, leading to the loss of the double helix configuration.