Anabolism is

Options

A. Sum total of metabolic reactions
B. Destructive metabolism
C. Constructive metabolism
D. Glycogenolysis

Answer

**Step-by-Step Solution:**

1. **Understanding Metabolism**: Metabolism consists of all the biochemical reactions that occur within a living organism. It can be divided into two main categories: anabolism and catabolism.

2. **Defining Anabolism**: Anabolism refers to the constructive metabolic processes that involve the synthesis of complex molecules from simpler ones. This includes the formation of macromolecules such as proteins, nucleic acids, and polysaccharides.

3. **Defining Catabolism**: In contrast, catabolism is the destructive metabolic process where complex molecules are broken down into simpler ones, releasing energy in the process.

4. **Energy Requirement**: Anabolic processes require energy input to build complex molecules, making them endergonic reactions. Conversely, catabolic processes release energy when breaking down molecules, classifying them as exergonic reactions.

5. **Analyzing the Options**:
- **Sum total of metabolic reactions**: This refers to metabolism as a whole, which includes both anabolism and catabolism. Therefore, this option is incorrect.
- **Destructive metabolism**: This term describes catabolism, not anabolism, making this option incorrect.
- **Constructive metabolism**: This accurately describes anabolism, as it involves the building of complex molecules, making this option correct.
- **Glycogenolysis**: This term refers specifically to the breakdown of glycogen, which is a catabolic process, thus incorrect.

6. **Conclusion**: The correct answer to the question "Anabolism is" is "constructive metabolism."

**Final Answer**: Constructive metabolism (Option C).

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