During strenuous muscular activity, hydrogens removed from sugar molecules are accepted temporarily by ........... to form ..........

Options

A. oxygen, water
B. pyruvate, lactic acid
C. myoglobin, carbaminohaemoglobin
D. oxygen, carbon dioxide

Explanation

**Step-by-Step Solution:**

1. **Understanding the Context**: The question pertains to the process of energy production during strenuous muscular activity, particularly focusing on anaerobic respiration.

2. **Identifying the Reactants**: During strenuous activity, the body breaks down sugar molecules (glucose) to release energy. This process involves the removal of hydrogen ions from these sugar molecules.

3. **Recognizing the Temporary Acceptors**: In anaerobic respiration, the hydrogen ions removed from the sugar molecules are temporarily accepted by a specific compound. This compound is pyruvate (or pyruvic acid), which is produced during glycolysis.

4. **Identifying the Products**: When hydrogen ions are accepted by pyruvate, the byproduct formed is lactic acid (or lactate). This accumulation of lactic acid in the muscles can lead to fatigue and cramps.

5. **Filling in the Blanks**: Based on the analysis:
- The first blank can be filled with "pyruvate".
- The second blank can be filled with "lactic acid".

6. **Final Answer**: During strenuous muscular activity, hydrogens removed from sugar molecules are accepted temporarily by **pyruvate** to form **lactic acid**.

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