Metabolic reaction involves

Options

A. Synthesis of biomolecules only
B. Breakdown of some biomolecules only
C. All physical changes which occur in objects around us
D. All chemical reactions which occur inside an organism

Explanation

**Step-by-Step Solution:**

1. **Understanding Metabolic Reactions**: Metabolic reactions refer to all the chemical processes that occur within living organisms. These reactions are essential for maintaining life and involve various biochemical pathways.

2. **Types of Metabolic Reactions**: Metabolic reactions can be categorized into two main types:
- **Anabolic Reactions**: These are constructive processes where smaller molecules are synthesized to form larger, more complex molecules. Anabolic reactions require energy input.
- **Catabolic Reactions**: These are destructive processes where larger molecules are broken down into smaller ones, releasing energy in the process.

3. **Chemical Nature of Metabolic Reactions**: All metabolic reactions are chemical in nature. They involve the transformation of substances through chemical changes, which is vital for growth, reproduction, and maintaining cellular functions.

4. **Conclusion**: Based on the definitions and types of metabolic reactions, the correct answer to the question is that metabolic reactions involve all chemical reactions that occur inside an organism. This encompasses both anabolic and catabolic processes.

**Final Answer**: All chemical reactions which occur inside an organism.

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