**Core Concept**
The ser-195-ala mutation in the chymotrypsin molecule refers to a change in the amino acid sequence of the enzyme, specifically at position 195 from serine (Ser) to alanine (Ala). This mutation affects the active site of the enzyme, which is crucial for its catalytic activity. Chymotrypsin is a serine protease, and the serine residue at position 195 plays a key role in its mechanism of action.

**Why the Correct Answer is Right**
The serine residue at position 195 in chymotrypsin is part of the catalytic triad, which includes histidine (His) and aspartic acid (Asp). The serine residue acts as a nucleophile, attacking the carbonyl carbon of the substrate peptide bond, while the histidine residue stabilizes the transition state and the aspartic acid residue provides a negative charge to facilitate the reaction. The ser-195-ala mutation would disrupt this catalytic triad, leading to a significant reduction in the enzyme's activity.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is not provided, so we cannot evaluate it.
**Option B:** This option is not provided, so we cannot evaluate it.
**Option C:** This option is not provided, so we cannot evaluate it.
**Option D:** This option is not provided, so we cannot evaluate it.

**Clinical Pearl / High-Yield Fact**
The ser-195-ala mutation in chymotrypsin highlights the importance of the active site in enzyme catalysis. This mutation demonstrates that even a single amino acid change can significantly impact the enzyme's activity, emphasizing the importance of precise amino acid sequences in enzyme function.

**Correct Answer:** D. The ser-195-ala mutation would render the chymotrypsin molecule inactive.