If volume of `CO_(2)` liberated during respiration is more than the volume of `O_(2)` used, then the respiratory substrate will be

Options

A. carbohydrate
B. fat
C. protein
D. organic acid

Explanation

To determine the respiratory substrate when the volume of carbon dioxide (CO₂) liberated during respiration is greater than the volume of oxygen (O₂) used, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Respiratory Quotient (RQ)**:
- The respiratory quotient (RQ) is defined as the ratio of the volume of CO₂ produced to the volume of O₂ consumed during respiration.
- Mathematically, it is expressed as:
\[ RQ = \frac{\text{Volume of } CO_2 \text{ produced}}{\text{Volume of } O_2 \text{ consumed}} \]

2. **Analyzing the Given Condition**:
- The problem states that the volume of CO₂ liberated is greater than the volume of O₂ used. This implies:
\[ \text{Volume of } CO_2 > \text{Volume of } O_2 \]
- Therefore, the RQ will be greater than 1:
\[ RQ > 1 \]

3. **Identifying the Respiratory Substrates**:
- Different respiratory substrates have specific RQ values:
- Carbohydrates: RQ = 1
- Fats: RQ = 0.7
- Proteins: RQ = 0.8
- Organic acids: RQ > 1
- Since we have established that RQ > 1, we can conclude that the substrate must be one that produces more CO₂ than O₂ consumed.

4. **Conclusion**:
- The only respiratory substrate that fits the condition of having an RQ greater than 1 is **organic acids**.

### Final Answer:
The respiratory substrate will be **organic acids**.