American Society for Clinical Pathology (ASCP) Technologist in Cytogenetics certification (ASCP CG) Practice Test

What happens to the enzymatic activity of trypsin as pH increases to 8?

1. The enzymatic activity decreases

2. The enzymatic activity remains unchanged

3. The enzymatic activity increases

4. The enzymatic activity is eliminated

The correct answer is: The enzymatic activity increases

Trypsin, a serine protease, is most active in a slightly alkaline pH environment, typically around pH 8. As the pH increases toward this optimal level, the ionic state of the active site and substrate binding sites of trypsin become more favorable, enhancing its ability to cleave peptide bonds. At lower pH levels, the enzyme may become protonated, which can hinder its function and lead to decreased enzymatic activity. Conversely, as the pH approaches 8, trypsin maintains an optimal configuration and remains active, thereby facilitating an increase in enzymatic activity. This is crucial for its role in digesting proteins in the small intestine, where the pH is naturally neutral to slightly alkaline. While other pH levels outside of this optimal range may diminish trypsin's activity or even eliminate it entirely, when the pH is increasing to 8, the enzymatic activity is indeed heightened, reflecting the enzyme's adaptation to its physiological environment.