21.  Enzymes that are secreted by a cell to hydrolyze reactions are  
A.  Apoenzymes
B.  Exoenzymes
C.  Constitutive enzymes
D.  Regulated enzymes
E.  Endoenzymes

22.  Enzymes that function inside a cell are  
A.  Apoenzymes
B.  Exoenzymes
C.  Constitutive enzymes
D.  Regulated enzymes
E.  Endoenzymes

23.  Enzymes that are always present, regardless of the amount of substrate are  
A.  Apoenzymes
B.  Axoenzymes
C.  Constitutive enzymes
D.  Regulated enzymes
E.  Endoenzymes

24.  When enzyme action stops due to a buildup of end product, this control is called  
A.  Negative feedback
B.  Competitive inhibition
C.  Enzyme induction
D.  Enzyme repression
E.  Feedback inhibition

25.  Each of the following are denaturing agents except  
A.  High temperature
B.  Low temperature
C.  High pH
D.  Low pH
E.  All of the choices are correct

26.  Feedback inhibition is best described as  
A.  Substrate binding to DNA, blocking enzyme transcription
B.  Product binding to DNA, blocking enzyme transcription
C.  Substrate binding to enzyme in non-competitive site
D.  Product binding to enzyme in non-competitive site
E.  None of the choices are correct

27.  Metabolic pathways that regenerate their starting point are called _____ pathways.  
A.  Linear
B.  Bi-directional
C.  Convergent
D.  Cyclic
E.  Divergent

28.  When the product of reaction A becomes the reactant of reaction B, the metabolic pathway is  
A.  Linear
B.  Bi-directional
C.  Convergent
D.  Cyclic
E.  Divergent

29.  Most electron carriers are  
A.  Coenzymes
B.  Enzymes
C.  Hydrogens
D.  Inorganic phosphate
E.  All of the choices are correct

30.  Exergonic reactions  
A.  Include synthesis of large carbohydrates
B.  Only occur in heterotrophs
C.  Occur during aerobic cellular respiration
D.  Do not occur in anaerobic cellular respiration
E.  Occur when ADP binds to inorganic phosphate to form ATP