Protein is a

Options

A. Macromolecule
B. Steroid
C. Fat
D. Micromolecule.

Answer

**Step-by-Step Solution:**

1. **Understanding Proteins**:
- Proteins are essential biomolecules that serve as the building blocks of the body. They play crucial roles in various biological processes.

2. **Composition of Proteins**:
- Proteins are composed of smaller units called amino acids. There are 20 different amino acids that can combine in various sequences to form a protein.

3. **Formation of Peptide Bonds**:
- Amino acids are linked together through peptide bonds. A peptide bond is formed when the carboxyl group of one amino acid reacts with the amino group of another amino acid, releasing a molecule of water in a condensation reaction.

4. **Classification of Proteins**:
- Proteins are classified as macromolecules due to their large size and complexity. They are made up of long chains of amino acids, which can consist of hundreds or thousands of amino acids.

5. **Exclusion of Other Options**:
- Proteins are not steroids or fats. Steroids are a type of lipid, and fats are also lipids, which are different classes of biomolecules. Additionally, proteins are not micromolecules, as they are composed of many smaller molecules (amino acids).

6. **Conclusion**:
- Therefore, the correct classification of proteins is that they are macromolecules.

**Final Answer**: Protein is a macromolecule.

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