Select the correct one w.r.t R.Q

Options

A. Its value is 0.9 for tripalmitin
B. Its value is 0.7 for organic acid
C. Its depend on the type of respiratory substrate
D. In floating respiration,R.Q is always greater than 1

Answer

To solve the question regarding the respiratory quotient (R.Q), let's analyze the options provided step by step.

### Step 1: Understand the Concept of R.Q
The respiratory quotient (R.Q) is defined as the ratio of the volume of carbon dioxide (CO2) produced to the volume of oxygen (O2) consumed during respiration. It provides insights into the type of substrate being metabolized.

**Hint:** Remember that R.Q values differ based on the type of substrate used in respiration.

### Step 2: Evaluate Each Option
1. **Option 1: Its value is 0.9 for tripalmitin.**
- Tripalmitin is a fat. The R.Q for fats is generally around 0.7. Therefore, this option is incorrect.

**Hint:** Recall that fats typically have lower R.Q values compared to carbohydrates.

2. **Option 2: Its value is 0.7 for organic acid.**
- Organic acids like malic acid have an R.Q greater than 1 (approximately 1.33). Thus, this option is also incorrect.

**Hint:** Organic acids often yield more CO2 than O2 consumed, leading to an R.Q greater than 1.

3. **Option 3: It depends on the type of respiratory substrate.**
- This statement is true. Different substrates (carbohydrates, fats, proteins) have different R.Q values. For example, carbohydrates have an R.Q of 1, fats have an R.Q of 0.7, and proteins have an R.Q of about 0.8.

**Hint:** Different substrates yield different amounts of CO2 and O2, affecting the R.Q.

4. **Option 4: In floating respiration, R.Q is always greater than 1.**
- Floating respiration typically involves the metabolism of proteins and carbohydrates. The R.Q for proteins is about 0.8, and for carbohydrates, it is 1. Therefore, this statement is incorrect as R.Q is not always greater than 1.

**Hint:** Floating respiration does not guarantee an R.Q greater than 1; it can be equal to or less than 1 depending on the substrate.

### Step 3: Conclusion
After evaluating all the options, the correct statement regarding R.Q is:
- **It depends on the type of respiratory substrate.**

**Final Answer:** The correct option is that R.Q depends on the type of respiratory substrate.