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

3. Energy & Cell Processes

Krebs Cycle

Anatomy & Physiology

3. Energy & Cell Processes

Krebs Cycle

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Multiple Choice

The Krebs cycle begins with the addition of acetyl CoA to which of the following?

Citrate

Succinate

Fumarate

Oxaloacetate

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Verified step by step guidance

Understand that the Krebs cycle, also known as the citric acid cycle, is a series of chemical reactions used by all aerobic organisms to generate energy through the oxidation of acetate derived from carbohydrates, fats, and proteins into carbon dioxide.

Recognize that the cycle begins with the combination of acetyl CoA, a two-carbon molecule, with a four-carbon molecule called oxaloacetate to form citrate, a six-carbon molecule.

Identify that oxaloacetate is regenerated at the end of the cycle, allowing the process to continue in a cyclic manner.

Note that the other options listed (citrate, succinate, fumarate) are intermediates in the Krebs cycle but are not the starting molecule that combines with acetyl CoA.

Conclude that the correct answer is oxaloacetate, as it is the molecule that combines with acetyl CoA to initiate the Krebs cycle.