If all the peptide bonds of protein are broken, then the remaining part is :

Options

A. Amide
B. Oligosaccharide
C. Polypeptide
D. Amino acid

Answer

To solve the question "If all the peptide bonds of protein are broken, then the remaining part is:", we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Proteins**:
- Proteins are large biomolecules made up of smaller units called amino acids. These amino acids are linked together by peptide bonds.

2. **Identifying Peptide Bonds**:
- A peptide bond is a covalent bond that forms between the carboxyl group of one amino acid and the amino group of another. This bond is what holds the amino acids together in a protein chain.

3. **Breaking Peptide Bonds**:
- If all the peptide bonds in a protein are broken, the protein is essentially hydrolyzed into its constituent amino acids. This means that the long chain of amino acids that make up the protein will be separated.

4. **Resulting Components**:
- After breaking all the peptide bonds, the only remaining components will be the individual amino acids.

5. **Evaluating Options**:
- Given the options:
- Amide: Incorrect, as it is unrelated to proteins.
- Oligosaccharide: Incorrect, as it pertains to carbohydrates.
- Polypeptide: Incorrect, as it still refers to a protein structure.
- Amino acid: Correct, as this is what remains after peptide bonds are broken.

6. **Conclusion**:
- Therefore, if all the peptide bonds of a protein are broken, the remaining part is amino acids.

### Final Answer:
The remaining part is **amino acids**.

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