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

What is a by-product of the Krebs cycle?

Glucose

Lactic acid

Carbon dioxide (CO2)

Oxygen (O2)

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Verified step by step guidance

Understand the Krebs cycle: 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.

Identify the inputs and outputs: The main inputs of the Krebs cycle are acetyl-CoA, NAD+, FAD, and ADP, while the outputs include ATP, NADH, FADH2, and carbon dioxide (CO2).

Focus on the by-products: During the Krebs cycle, carbon dioxide (CO2) is released as a by-product when acetyl-CoA is oxidized. This occurs in several steps of the cycle where decarboxylation reactions take place.

Differentiate from other substances: Glucose is not a by-product of the Krebs cycle; it is a substrate that is broken down into pyruvate before entering the cycle. Lactic acid is produced during anaerobic respiration, not the Krebs cycle. Oxygen (O2) is used in the electron transport chain, not produced in the Krebs cycle.

Conclude with the correct by-product: Carbon dioxide (CO2) is the correct by-product of the Krebs cycle, as it is released during the conversion of acetyl-CoA into energy.