In anaerobic respiration of muscles, the pyruvic acid is changed to

Options

A. Alcohol
B. Acetaldehyde
C. Acetyl CoA
D. Lactic acid

Answer

**Step-by-Step Solution:**

1. **Understand Anaerobic Respiration**: Anaerobic respiration occurs in the absence of oxygen. In muscles, this process is crucial during intense exercise when oxygen supply is limited.

2. **Identify the Starting Point**: The process begins with glycolysis, where glucose is broken down into pyruvic acid. This step occurs in the cytoplasm of the cell and is common to both aerobic and anaerobic respiration.

3. **Recognize the Fate of Pyruvic Acid**: In anaerobic conditions, specifically in muscle cells, pyruvic acid does not enter the aerobic pathway (which would lead to the Krebs cycle). Instead, it is converted into lactic acid.

4. **Write the Chemical Equation**: The conversion can be summarized as follows:
\[ \text{Pyruvic Acid (C}_3\text{H}_4\text{O}_3\text{)} \rightarrow \text{Lactic Acid (C}_3\text{H}_6\text{O}_3\text{)} \]

5. **Energy Yield**: During this conversion, only a small amount of energy (2 ATP molecules) is produced, which is significantly less than what is produced during aerobic respiration.

6. **Conclusion**: Therefore, in anaerobic respiration of muscles, pyruvic acid is changed to lactic acid.

**Final Answer**: In anaerobic respiration of muscles, the pyruvic acid is changed to lactic acid.

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