Respiration is

Options

A. anabolic and exothermic
B. anabolic and endothermic
C. catabolic and endothermic
D. catabolic exothermic

Answer

### Step-by-Step Solution:

1. **Understanding the Terms:**
- **Anabolic Process:** This is a metabolic pathway that constructs molecules from smaller units. It requires energy input.
- **Catabolic Process:** This is a metabolic pathway that breaks down molecules into smaller units. It releases energy.

2. **Understanding Exothermic and Endothermic Reactions:**
- **Exothermic Reaction:** A reaction that releases energy, usually in the form of heat.
- **Endothermic Reaction:** A reaction that absorbs energy from its surroundings.

3. **Analyzing Respiration:**
- Respiration involves the breakdown of complex molecules (like glucose) into simpler molecules (like carbon dioxide and water).
- This breakdown process releases energy, primarily in the form of ATP (adenosine triphosphate).

4. **Categorizing Respiration:**
- Since respiration breaks down complex molecules into simpler ones, it is classified as a **catabolic process**.
- Because it releases energy during this breakdown, it is also classified as an **exothermic reaction**.

5. **Conclusion:**
- Based on the definitions and the analysis of respiration, we conclude that respiration is a **catabolic and exothermic** process.
- Therefore, the correct answer is **option D: catabolic and exothermic**.