In the primary structure of a protein , amino acids are linked due to the presence of

Options

A. Hydrogen bonds
B. Peptide bonds
C. `-S-S-` linkages
D. lonic bonds

Answer

To solve the question regarding the primary structure of a protein and how amino acids are linked, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Protein Structure**:
- Proteins are complex molecules that play critical roles in biological processes. They are made up of smaller units called amino acids.

2. **Identifying the Types of Protein Structures**:
- Proteins have four levels of structure: primary, secondary, tertiary, and quaternary. The primary structure is the most basic level, consisting of a linear sequence of amino acids.

3. **Amino Acids as Building Blocks**:
- There are 20 different amino acids that can combine in various sequences to form proteins. Each protein has a unique sequence of amino acids.

4. **Linking Amino Acids**:
- In the primary structure, amino acids are linked together through specific chemical bonds.

5. **Formation of Peptide Bonds**:
- The bond that links one amino acid to another in the primary structure is called a peptide bond. This bond forms through a dehydration synthesis reaction, where a molecule of water is released.

6. **Conclusion**:
- Therefore, in the primary structure of a protein, amino acids are linked due to the presence of peptide bonds.

### Final Answer:
In the primary structure of a protein, amino acids are linked due to the presence of **peptide bonds**.

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