19. Enzymes

Match the terms (a) enzyme-substrate complex, (b) enzyme and (c) substrate with each of the following:

______ Has a structure that fits the active site of an enzyme. 

______ Can possess a tertiary structure that recognizes the substrate. 

______ The combination of an enzyme with the substrate. 

Match the terms (a) enzyme-substrate complex, (b) enzyme and (c) substrate with each of the following:

______ pyruvate

______ lipase

______ galactose transaminase

______ amylase

Match the terms (1) enzyme–substrate complex, (2) enzyme, and (3) substrate with each of the following:

a. has a tertiary structure that recognizes the substrate

Match the terms (1) enzyme–substrate complex, (2) enzyme, and (3) substrate with each of the following:

b. the combination of an enzyme with the substrate

A substrate is held in the active site of an enzyme by attractive forces between the substrate and the amino acid side chains. For the outlined regions A, B, and C on the following substrate molecule:

<IMAGE>

b. Could the amino acids serine, lysine, or glutamate be present in the active site? Support your answer.

If each of the following amino acid side chains is present in the active site of an enzyme, indicate whether it would (a) serve a catalytic function, (b) serve to hold the substrate, or (c) both.

a. aspartate <IMAGE>

If each of the following amino acid side chains is present in the active site of an enzyme, indicate whether it would (a) serve a catalytic function, (b) serve to hold the substrate, or (c) both.

d. lysine <IMAGE>

What type of interactions between an enzyme and its substrate help to stabilize ES?

Match the terms (1) ES with the following descriptions:

a. has a tertiary structure that recognizes the substrate

b. is the combination of an enzyme with the substrate

c. has a structure that fits the active site of an enzyme

Match the terms (3) substrate with the following descriptions:

a. has a tertiary structure that recognizes the substrate

b. is the combination of an enzyme with the substrate

c. has a structure that fits the active site of an enzyme