Question

1. Which amino acid is not one that may be targeted for phosphorylation to modulate the activity of an enzyme?

A. Tyr
B. HIs
C. Ser
D. Ala
E.Thr
2. which two factor can contribute to enzyme catalysis?
A. weak noncovalent interactions between enzyme and substrate and transient covalent bonds between enzyme and substrate
B. permanent covalent bonds between substrate and product and binding energy between enzyme and product
C. weak noncovalent interactions between enzyme and binding energy between enzyme and product
D. permanent covalent bonds between substrate and transient covalent bonds between enzyme and substrate
E. re-solvation of the enzyme
3. How do enzymes achieve their maximum velocity?
A. excess enzyme is self-inhibitory, blocking catalysis
B. when the rate of catalysis matches the rate of ES complex formation the enzyme reaches its maximum velocity
C. at high substrate concentrations, the enzymes is saturated and can not catalyze any faster
D. there is no maximum velocity for an enzyme

Answer 1

Explanation: 1.D. Ala (Alanine) is not typically targeted for phosphorylation.

2.A. Weak noncovalent interactions between enzyme and substrate and transient covalent bonds between enzyme and substrate contribute to enzyme catalysis.

3.C. At high substrate concentrations, the enzyme is saturated and cannot catalyze any faster, so it has reached its maximum velocity.