Oxidation of glucose to `CO_(2)` and water occurs during

Options

A. Glycolysis
B. oxidative phosphorylation
C. Krebs cycle
D. All the above

Answer

To answer the question regarding the oxidation of glucose to carbon dioxide and water, we need to understand the processes involved in aerobic respiration. Here’s a step-by-step breakdown of the solution:

### Step-by-Step Solution:

1. **Understanding Aerobic Respiration**:
- Aerobic respiration is the process by which glucose is oxidized to produce carbon dioxide (CO₂), water (H₂O), and energy in the form of ATP.

2. **Glycolysis**:
- The first step in aerobic respiration is glycolysis, where one molecule of glucose (6 carbons) is broken down into two molecules of pyruvate (3 carbons each). This process occurs in the cytoplasm and produces a small amount of ATP and NADH.

3. **Formation of Acetyl-CoA**:
- The pyruvate produced in glycolysis is then transported into the mitochondria, where it undergoes oxidative decarboxylation to form Acetyl-CoA. During this process, one carbon is released as CO₂.

4. **Krebs Cycle (Citric Acid Cycle)**:
- Acetyl-CoA enters the Krebs cycle, which takes place in the mitochondrial matrix. Here, Acetyl-CoA is further oxidized, and more CO₂ is released. The Krebs cycle also produces NADH and FADH₂, which are important for the next stage of respiration.

5. **Oxidative Phosphorylation**:
- The final stage of aerobic respiration is oxidative phosphorylation, which occurs in the inner mitochondrial membrane. The NADH and FADH₂ produced in the previous steps donate electrons to the electron transport chain, leading to the production of a large amount of ATP and the reduction of oxygen to form water (H₂O).

6. **Conclusion**:
- Since the complete oxidation of glucose to CO₂ and water involves all three processes (glycolysis, Krebs cycle, and oxidative phosphorylation), the correct answer to the question is "all of the above".

### Final Answer:
The oxidation of glucose to carbon dioxide and water occurs during **all of the above** (glycolysis, Krebs cycle, and oxidative phosphorylation).

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