R.Q. would depend upon

Options

A. Nature of enzymes
B. Nature of substrate
C. Amount of `CO_(2)` released
D. Amount of `O_(2)` utilised.

Answer

### Step-by-Step Solution:

1. **Understanding RQ (Respiratory Quotient)**:
- RQ is defined as the ratio of the volume of carbon dioxide (CO2) produced to the volume of oxygen (O2) consumed during respiration.
- Mathematically, it can be expressed as:
\[ RQ = \frac{\text{Volume of CO2 produced}}{\text{Volume of O2 consumed}} \]

2. **Factors Affecting RQ**:
- The RQ value can vary depending on the type of substrate being metabolized during respiration. Different substrates yield different amounts of CO2 and O2.
- For example, when glucose is the substrate, the reaction can be summarized as:
\[ C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O \]
- In this case, the RQ is 1 because the amount of CO2 produced equals the amount of O2 consumed.

3. **Nature of Substrate**:
- The nature of the substrate is crucial in determining the RQ. Carbohydrates, fats, and proteins have different RQ values:
- Carbohydrates (like glucose) typically have an RQ of 1.
- Fats have an RQ of about 0.7.
- Proteins have an RQ that can vary but is generally around 0.8.

4. **Conclusion**:
- The RQ does not depend on the nature of enzymes, the amount of CO2 released, or the amount of O2 utilized directly. Instead, it is primarily influenced by the type of substrate being metabolized.

### Final Answer:
The RQ (Respiratory Quotient) would depend upon the **nature of the substrate**.

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