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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 Heart2h 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

Pyruvate Oxidation

3. Energy & Cell Processes

Pyruvate Oxidation: Videos & Practice Problems

Video Lessons Practice Worksheet

Topic summary

Pyruvate oxidation, the second step of cellular respiration, occurs in the mitochondrial matrix, converting 2 pyruvate molecules from glycolysis into 2 Acetyl CoA molecules. This process also produces 2 NADH and 2 carbon dioxide (CO2) molecules through oxidation, where pyruvate loses electrons, transferring them to NAD+, forming NADH. Each pyruvate, containing 3 carbon atoms, loses one carbon as CO2, while the remaining carbons attach to CoA. The Acetyl CoA then enters the Krebs cycle, continuing the energy extraction from glucose.

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Pyruvate Oxidation

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Pyruvate Oxidation Video Summary

Pyruvate oxidation is a crucial step in cellular respiration that occurs in the mitochondrial matrix, following glycolysis, which produces two pyruvate molecules from one glucose molecule. During pyruvate oxidation, each pyruvate is converted into Acetyl CoA, a vital molecule that enters the Krebs Cycle. This process results in the production of two Acetyl CoA molecules, two NADH molecules, and two carbon dioxide (CO₂) molecules.

In terms of chemical transformations, pyruvate undergoes oxidation, meaning it loses electrons. The electrons lost by pyruvate are accepted by NAD⁺, which is reduced to NADH. Each pyruvate contains three carbon atoms, but one carbon atom is released as CO₂ during the oxidation process. Consequently, from the two pyruvate molecules, two CO₂ molecules are produced, while the remaining carbon atoms are converted into two Acetyl CoA molecules.

To summarize, pyruvate oxidation efficiently transforms the products of glycolysis into forms that can be utilized in subsequent stages of cellular respiration, specifically the Krebs Cycle. This step is essential for the continuation of energy production within the cell, highlighting the interconnectedness of metabolic pathways.

Problem

Each of the following describes the pyruvate oxidation reaction except that _____________________.
a) It connects glycolysis to the citric acid cycle.
b) Each pyruvate is converted to an acetyl-CoA molecule.
c) NAD⁺ is reduced to NADH.
d) This reaction occurs within the cytoplasm.
e) Carbon dioxide is released as a by-product.

It connects glycolysis to the citric acid cycle.

Each pyruvate is converted to an acetyl-CoA molecule.

NAD⁺ is reduced to NADH.

This reaction occurs within the cytoplasm.

Carbon dioxide is released as a by-product.

Problem

In aerobic cellular respiration, pyruvate molecules must be transformed through a process called pyruvate oxidation before they can be broken down in the Krebs Cycle. What are the products of pyruvate oxidation?
a) Acetyl CoA, O₂, and ATP.
b) Acetyl and CO₂.
c) Acetyl CoA, FADH₂, and CO₂.
d) Acetyl CoA, NADH, and CO₂.
e) Acetyl CoA, NAD⁺, ATP, and CO₂.

Acetyl CoA, O₂, and ATP.

Acetyl and CO₂.

Acetyl CoA, FADH₂, and CO₂.

Acetyl CoA, NADH, and CO₂.

Acetyl CoA, NAD⁺, ATP, and CO₂.

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What is pyruvate oxidation and where does it occur?

Pyruvate oxidation is the second step of cellular respiration, following glycolysis. It occurs in the mitochondrial matrix. During this process, each pyruvate molecule produced from glycolysis is converted into Acetyl CoA. This conversion involves the oxidation of pyruvate, where it loses electrons that are transferred to NAD⁺, forming NADH. Additionally, one carbon atom from each pyruvate is released as CO₂. The resulting Acetyl CoA molecules then enter the Krebs cycle for further energy extraction.

What are the products of pyruvate oxidation?

Pyruvate oxidation produces several key molecules: 2 Acetyl CoA, 2 NADH, and 2 CO₂ molecules. Each pyruvate molecule, containing 3 carbon atoms, loses one carbon as CO₂, while the remaining carbons attach to CoA to form Acetyl CoA. The electrons lost during the oxidation of pyruvate are transferred to NAD⁺, forming NADH. These products are crucial for the continuation of cellular respiration, as Acetyl CoA enters the Krebs cycle, and NADH is used in the electron transport chain.

How does pyruvate oxidation contribute to cellular respiration?

Pyruvate oxidation is a critical step in cellular respiration as it bridges glycolysis and the Krebs cycle. By converting pyruvate into Acetyl CoA, it prepares the substrate for the Krebs cycle, where further energy extraction occurs. Additionally, the NADH produced during pyruvate oxidation carries high-energy electrons to the electron transport chain, contributing to the generation of ATP. The CO₂ released is a waste product that is expelled from the cell. Overall, pyruvate oxidation ensures the efficient continuation of cellular respiration and energy production.

What happens to the carbon atoms in pyruvate during pyruvate oxidation?

During pyruvate oxidation, each pyruvate molecule, which contains 3 carbon atoms, undergoes a transformation. One of the carbon atoms is released as a CO₂ molecule. The remaining two carbon atoms are attached to Coenzyme A (CoA) to form Acetyl CoA. This process results in the production of 2 CO₂ molecules and 2 Acetyl CoA molecules from the original 2 pyruvate molecules produced during glycolysis. The Acetyl CoA then enters the Krebs cycle for further metabolic processing.

Why is NADH production important in pyruvate oxidation?

NADH production during pyruvate oxidation is crucial because NADH serves as an electron carrier in cellular respiration. When pyruvate is oxidized, it loses electrons that are transferred to NAD⁺, forming NADH. These high-energy electrons carried by NADH are later used in the electron transport chain to generate ATP, the primary energy currency of the cell. Thus, the production of NADH during pyruvate oxidation is essential for the efficient production of ATP and overall cellular energy metabolism.