Metabolic pathway that takes place during the formation of `CO_(2)` is

Options

A. Glycolysis
B. Fermentation
C. ETS
D. Reduction of Acetaldehyde

Answer

To answer the question about the metabolic pathway that takes place during the formation of carbon dioxide, we will analyze each option provided:

1. **Glycolysis**:
- Glycolysis is the metabolic pathway that converts glucose into pyruvate. This process occurs in the cytoplasm and does not directly produce carbon dioxide. However, the pyruvate produced can enter the citric acid cycle (Krebs cycle), where carbon dioxide is released as a byproduct during the oxidation of pyruvate. Therefore, while glycolysis itself does not produce CO₂, it leads to a pathway that does.

2. **Fermentation**:
- Fermentation is an anaerobic process that occurs when oxygen is not present. In alcoholic fermentation (like that in yeast), glucose is converted into ethanol and carbon dioxide. However, in lactic acid fermentation (which occurs in muscle cells during intense exercise), glucose is converted into lactic acid without the release of carbon dioxide. Since the question does not specify the type of fermentation, this option is ambiguous.

3. **Electron Transport Chain**:
- The electron transport chain is a series of reactions that occur in the mitochondria during aerobic respiration. This process is primarily responsible for ATP production and does not produce carbon dioxide directly. Instead, it relies on the products of glycolysis and the citric acid cycle, where CO₂ is produced.

4. **Reduction of Acetaldehyde**:
- The reduction of acetaldehyde does not produce carbon dioxide. Instead, acetaldehyde is formed from pyruvate through decarboxylation (which releases CO₂), but the reduction itself does not involve the release of carbon dioxide.

Based on the analysis of these pathways, the correct answer to the question is **Glycolysis**, as it is the only pathway that is directly linked to the production of carbon dioxide through subsequent reactions in aerobic respiration.

**Final Answer**: Glycolysis

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