The sum total of chemical reactions occurring in our body is called

Options

A. Metabolism
B. Homeostasis
C. Irritability
D. Catabolism

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for the term that describes the sum total of all chemical reactions occurring in the body.

2. **Analyzing the Options**:
- **Option A: Metabolism** - This term refers to all the biochemical processes that occur within a living organism, including both the building up and breaking down of substances.
- **Option B: Homeostasis** - This refers to the maintenance of stable internal conditions in an organism.
- **Option C: Irritability** - This term describes the ability of an organism to respond to stimuli.
- **Option D: Catabolism** - This is a part of metabolism that specifically refers to the breakdown of complex molecules into simpler ones.

3. **Identifying the Correct Answer**: Since the question asks for the sum total of all chemical reactions, the correct answer is **Metabolism** (Option A), as it encompasses both the anabolic (building up) and catabolic (breaking down) processes.

4. **Explaining Metabolism**: Metabolism is divided into two main categories:
- **Anabolism**: This involves the synthesis of complex molecules from simpler ones, which is essential for growth and repair.
- **Catabolism**: This involves the breakdown of complex molecules into simpler ones, releasing energy that can be used by the body.

5. **Conclusion**: The correct answer to the question is **Metabolism**, as it represents the totality of chemical reactions in the body.

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