A zinc ion in the active site of an enzyme can speed upthe reaction by:
A. Making a bound water molecule a more powerful nucleophile bydrawing electron density toward itself and facilitatingdeprotonation of the water
B. Orienting substrates for reaction
C. Stabilizing an anionic intermediate
D. All of these
E. None of these
The role of serine at the active site of serineproteases is to act as a ___ catalyst, while the histidine residueserves as an ___ catalyst.
A. acid-base, covalent
B. anionic; ionic
C. covalent; acid-base
D. strong; weak
E. weak; strong
The active site of an enzyme is being investigated bymutagenesis to determine the stability of the enzyme conformationfollowing substrate binding. A leucine is replaced by glycine. Thischange will:
A. Destabilize the enzyme
B. Stabilize the enzyme
C. Have no effect on the enzyme
