Which of the following will not denature a protein?

Options

A. Temperatures above `100^@C `
B. Strong acids or strong bases
C. Alcohol
D. Distilled water

Explanation

To determine which of the following will not denature a protein, we need to understand what denaturation is and the conditions that typically cause it.

### Step-by-Step Solution:

1. **Understanding Protein Structure**: Proteins have different levels of structure: primary, secondary, tertiary, and quaternary. Denaturation refers to the process where proteins lose their higher-order structures (secondary, tertiary, and quaternary) without breaking the peptide bonds of the primary structure.

2. **Identifying Denaturing Conditions**:
- **High Temperature**: Temperatures above 100 degrees Celsius can cause proteins to denature. This is because the heat disrupts the hydrogen bonds and other interactions that maintain the protein's structure.
- **Strong Acids or Bases**: The presence of strong acids or bases can alter the pH and disrupt ionic bonds and hydrogen bonds, leading to denaturation.
- **Alcohol**: Alcohol can disrupt the hydrogen bonds within proteins, leading to denaturation as well.

3. **Analyzing Distilled Water**: Distilled water is a neutral and stable compound. It does not alter the pH or introduce any extreme conditions that would disrupt the protein structure. Therefore, it does not cause denaturation.

4. **Conclusion**: Among the options provided, distilled water is the only condition that does not lead to the denaturation of proteins.

### Final Answer:
The correct option is **distilled water**, as it does not denature proteins.

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