Select the correct statement w.r.t RQ.

Options

A. Its value is 0.9 for tripalmitin
B. Its value is 0.7 for organic acids
C. It depends upon the type of respiratory-substrate
D. In floating respiration, RQ is always` gt 1`

Answer

To solve the question regarding the correct statement with respect to the Respiratory Quotient (RQ), we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Definition of RQ**:
- The 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, RQ = CO2 produced / O2 consumed.

2. **Identify the RQ Values for Different Substrates**:
- Different substrates yield different RQ values:
- Carbohydrates: RQ = 1.0
- Proteins: RQ = 0.8
- Fats: RQ = 0.7
- Organic acids: RQ > 1.0

3. **Clarify Misconceptions**:
- The statement about tripalmitin (a fat) having an RQ of 0.9 is incorrect. As a fat, its RQ should be 0.7.
- The statement that RQ is always greater than 1 during respiration involving fats and carbohydrates is also incorrect. This is true for organic acids, not for fats and carbohydrates.

4. **Identify the Correct Statement**:
- The correct statement regarding RQ is that it is substrate-dependent, meaning that the RQ value varies based on the type of substrate being used for respiration.
- Thus, the correct option would be the one that states that RQ values differ for fats, proteins, and carbohydrates, confirming that RQ is substrate-dependent.

### Conclusion:
The correct statement with respect to RQ is that it is substrate-dependent, with different values for carbohydrates, fats, and proteins.

---