Table of contents

1. Matter and Measurements4h 31m
2. Atoms and the Periodic Table5h 23m
3. Ionic Compounds2h 18m
4. Molecular Compounds2h 18m
5. Classification & Balancing of Chemical Reactions3h 17m
6. Chemical Reactions & Quantities2h 27m
7. Energy, Rate and Equilibrium3h 46m
8. Gases, Liquids and Solids3h 25m
9. Solutions4h 10m
10. Acids and Bases3h 29m
11. Nuclear Chemistry56m
BONUS: Lab Techniques and Procedures1h 38m
BONUS: Mathematical Operations and Functions47m
12. Introduction to Organic Chemistry1h 34m
13. Alkenes, Alkynes, and Aromatic Compounds2h 12m
14. Compounds with Oxygen or Sulfur1h 6m
15. Aldehydes and Ketones1h 1m
16. Carboxylic Acids and Their Derivatives1h 11m
17. Amines39m
18. Amino Acids and Proteins1h 51m
19. Enzymes1h 37m
20. Carbohydrates1h 41m
21. The Generation of Biochemical Energy2h 8m
22. Carbohydrate Metabolism2h 22m
23. Lipids2h 26m
24. Lipid Metabolism1h 45m
25. Protein and Amino Acid Metabolism1h 37m
26. Nucleic Acids and Protein Synthesis2h 54m

26. Nucleic Acids and Protein Synthesis

Nitrogenous Bases

GOB Chemistry

26. Nucleic Acids and Protein Synthesis

Nitrogenous Bases

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0:30 minutes

Problem 91a

Textbook Question

Identify each of the following bases as a pyrimidine or a purine:
a. cytosine

Verified step by step guidance

Understand the difference between pyrimidines and purines: Pyrimidines are single-ring nitrogenous bases, while purines are double-ring nitrogenous bases.

Recall the common pyrimidines: cytosine, thymine, and uracil. These are characterized by their single-ring structure.

Recall the common purines: adenine and guanine. These are characterized by their double-ring structure.

Examine the given base, cytosine, and identify its structure. Cytosine is a single-ring nitrogenous base.

Based on the structure of cytosine, classify it as a pyrimidine because it has a single-ring structure.

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Key Concepts

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

Pyrimidines and Purines

Pyrimidines and purines are the two categories of nitrogenous bases found in nucleic acids. Pyrimidines, which include cytosine, thymine, and uracil, have a single six-membered ring structure. In contrast, purines, such as adenine and guanine, consist of a fused double-ring structure. Understanding the structural differences between these bases is essential for classifying them correctly.

Cytosine

Cytosine is one of the four primary nitrogenous bases in DNA and RNA. It is classified as a pyrimidine due to its single-ring structure. Cytosine pairs with guanine in DNA and RNA, playing a crucial role in the genetic code and the stability of nucleic acid structures. Recognizing cytosine's classification helps in understanding its function in genetic information.

Base Pairing

Base pairing refers to the specific hydrogen bonding between nitrogenous bases in DNA and RNA, which is fundamental for the structure of nucleic acids. In DNA, adenine pairs with thymine, and cytosine pairs with guanine. This complementary pairing is vital for DNA replication and transcription processes. Understanding base pairing is crucial for grasping how genetic information is stored and transmitted.