21. The ability of CTP to bind to aspartate carbamoyltransferase and shut down the synthesis of more CTP is an example of

A. enzyme induction
B. enzyme repression
C. feedback inhibition of enzyme activity
D. none of these

22. Oxidation is the

A. loss of proton
B. gain of electron
C. loss of electron
D. gain of protons

23. Denaturation of an enzyme refers to the

A. improper arrangement of the enzyme in a metabolic pathway
B. loss of the enzymes proper shape
C. formation of the enzymes proper shape
D. formation of a new isozyme for that enzyme