Question

Chymotrypsin serves as a catalyst in the "Hydrolysis" of pepdite bonds - found in carboxylic groups of amino acids, which consist of aromatic pedand groups and large hydrophobic groups. Chymotrypsin is also known to serve as a catalyst in the Hydrolysis of "ester - and amide bonds" , found in hydrophobic groups.

1. Would you expect the K_Mof the reactions of Chymotrypsin with the different substrates to have the same value ? explain your reasoning.

2. Would you expect the V_maxof the reactions of Chymotrypsin with the different substrates to have the same value ? explain your reasoning.

3. Would you expect the " pH-dependence " of the "hydrolysis - reactions" of the different substrates to be the same for all substrates ? explain your reasoning.

Answer 1

The chymotrypsn is an enzyme used in the hydrolysis of peptides.

I.e. in the case of peptides, the KM value (the affinity to bind the substrate) is high, as a result, the rate of product formation (Vmax) increases.

Since there is a formation of acid as the result of hydrolysis of peptide (amide) bond, the enzyme is highly pH dependent.

Now, 1. The KM value decreases with other substrates.

Explanation: The other substrates may not be able to bind effectively with other substrates. As a result, the KM value is not same.

2. The Vmax value also decreases.

Explanation: As the enzyme can't effectively bnd with the other substrates, the rate of product formation will not be same.

3. The pH dependence of the enzyme does also decrease.

Explanation: As the product with other substrates may not be acid, the pH dependence of the enzyme may not be same.