During respiration, breakdown of respiratory substrate takes place in small steps or stages. This ensures :-

Options

A. Trapping of released energy into ATP
B. Constant temperature throghout the process of respiration
C. Production of number of useful intermediates
D. All of these

Answer

**Step-by-Step Solution:**

1. **Understanding Respiration:**
- Respiration is a catabolic process where organic substrates, primarily glucose, are broken down to release energy. This process occurs in multiple stages rather than a single step.

2. **Energy Release:**
- The breakdown of glucose occurs through a series of enzymatic reactions. Each step releases a small amount of energy, which is crucial for cellular functions. This energy is captured in the form of ATP (adenosine triphosphate).

3. **Glycolysis:**
- The first stage of respiration is glycolysis, which involves 10 enzymatic steps. During glycolysis, one glucose molecule is converted into two molecules of pyruvate. Each step produces different intermediates that can be utilized in other metabolic processes.

4. **Importance of Stepwise Breakdown:**
- If glucose were to be converted to pyruvate in a single step, a large amount of energy would be released all at once. This sudden release could generate excessive heat, potentially denaturing enzymes and disrupting cellular processes.

5. **Trapping Energy Efficiently:**
- By breaking down glucose in small steps, the energy released can be efficiently trapped in ATP. This allows cells to maintain a stable temperature and ensures that enzymes remain active and functional.

6. **Production of Intermediates:**
- The stepwise breakdown also results in the production of various intermediates, which can be used in other metabolic pathways, contributing to the overall metabolic flexibility of the cell.

7. **Conclusion:**
- Therefore, the breakdown of respiratory substrates in small steps ensures efficient energy capture, maintains a stable temperature, and produces numerous intermediates for various cellular processes.

**Final Answer:**
The breakdown of respiratory substrates in small steps ensures efficient energy capture, production of intermediates, and maintenance of a stable temperature. Thus, the correct answer is option 4: All of these are correct.

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