Work Sheet 11

Enzyme Mechanisms-Serine Proteases

1. Describe the general roles played by the serine, histidine and aspartate residues in the active site of chymotrypsin.

2. Explain why histidine is found in the active site of many diverse proteases.

3. Diagram the catalytic mechanism of chymotrypsin, identifying the two transition states.

4. Give two examples of other serine proteases and their general physiological role.

5. Define the term proenzyme and give an example of a physiological role for proenzymes.

© Sturm 2014