The building unit of all proteins are

Options

A. monosaccharides
B. lipids
C. amino acids
D. primary amines

Answer

**Step-by-Step Solution:**

1. **Understanding Proteins**:
- Proteins are large biomolecules that play critical roles in the body. They are essential for various functions, including structure, function, and regulation of the body's tissues and organs.

2. **Identifying the Building Blocks**:
- The question asks for the building unit of proteins. The fundamental components that make up proteins are known as amino acids.

3. **Structure of Amino Acids**:
- Each amino acid consists of a central carbon atom (C) bonded to:
- An amine group (NH2)
- A carboxylic acid group (COOH)
- A hydrogen atom (H)
- A variable side chain (R group) that determines the specific characteristics of each amino acid.

4. **Linking Amino Acids**:
- Amino acids are linked together by peptide bonds to form polypeptides. When multiple amino acids are linked, they create a protein.

5. **Conclusion**:
- Therefore, the building unit of all proteins is **amino acids**.

**Final Answer**: The building unit of all proteins are **amino acids**.

---