The 20 different amino acids have different

Options

A. R-groups
B. carboxylic groups
C. peptide bonds
D. amino groups.

Answer

**Step-by-Step Solution:**

1. **Understanding Amino Acids**: Amino acids are the building blocks of proteins. There are 20 different amino acids that combine to form proteins.

2. **Structure of Amino Acids**: Each amino acid has a basic structure that includes:
- An amino group (-NH2)
- A carboxylic group (-COOH)
- A hydrogen atom
- A variable side chain (R group)

3. **Identifying the Unique Feature**: The unique feature that differentiates the 20 amino acids is the side chain or R group. Each amino acid has a distinct R group that determines its properties and functions.

4. **Evaluating the Options**:
- **Option 1: R groups** - This is correct. The 20 different amino acids have different R groups.
- **Option 2: Carboxylic groups** - Incorrect. All amino acids have the same carboxylic group.
- **Option 3: Peptide bonds** - Incorrect. Peptide bonds are the linkages formed between amino acids, not a distinguishing feature.
- **Option 4: Amino groups** - Incorrect. All amino acids have the same amino group.

5. **Conclusion**: The correct answer is that the 20 different amino acids have different R groups.

**Final Answer**: The 20 different amino acids have different R groups (Option 1).

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