When respiratory substrate is cereal/ starch/ sprouting potato tuber, then RQ value is

Options

A. (a) zero
B. (b) unity
C. (c) greater than unity
D. (d) less than unity

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.
- The formula for RQ is:
\[ RQ = \frac{\text{Volume of CO2 evolved}}{\text{Volume of O2 consumed}} \]

2. **Identifying the Respiratory Substrate**:
- The question states that the respiratory substrate is cereal, starch, or sprouting potato tuber.
- All these substrates are primarily carbohydrates.

3. **RQ Values for Different Substrates**:
- The RQ value varies depending on the type of respiratory substrate:
- For carbohydrates (like starch), the RQ value is 1.
- For proteins, the RQ value is approximately 0.9.
- For fats, the RQ value is approximately 0.7.

4. **Calculating RQ for Carbohydrates**:
- When carbohydrates are used as the respiratory substrate, the general equation for aerobic respiration can be represented as:
\[ \text{C}_6\text{H}_{12}\text{O}_6 + 6\text{O}_2 \rightarrow 6\text{CO}_2 + 6\text{H}_2\text{O} + \text{Energy} \]
- In this reaction, for every 6 molecules of O2 consumed, 6 molecules of CO2 are produced.

5. **Determining the RQ Value**:
- Plugging the values into the RQ formula:
\[ RQ = \frac{6 \text{ CO2}}{6 \text{ O2}} = 1 \]
- Therefore, the RQ value for carbohydrates is 1.

6. **Conclusion**:
- Since the respiratory substrates mentioned in the question are all carbohydrates, the RQ value is unity (1).

### Final Answer:
The RQ value when the respiratory substrate is cereal, starch, or sprouting potato tuber is **1**.

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