Question :
31.In which of the following pairs of substances both members : 1309698
31.In which of the following pairs of substances are both members of the pair zymogens?
a.pepsin and pepsinogen
b.proelastase and elastase
c.prothrombin and pepsinogen
d.more than one correct response
e.no correct response
32.Which of the following is not a water-soluble vitamin?
a.vitamin C
b.vitamin A
c.vitamin D
d.more than one correct response
e.no correct response
33.Which of the following pairings of vitamins and functions is correct?
a.vitamin E; an antioxidant
b.vitamin C; a coenzyme
c.vitamin D; maintenance of mucous membranes
d.more than one correct response
e.no correct response
34.Which of the following B vitamins has a structure in which a metal atom is present?
a.folate
b.biotin
c.vitamin B12
d.more than one correct response
e.no correct response
35.Which of the following statements concerning sources for B vitamins is correct?
a.Most fruits are poor sources.
b.Most vegetables are good sources.
c.Meat and dairy products are good sources.
d.More than one correct response.
e.No correct response.
Use the following to answer the questions below:
In each of the following multiple-choice questions, characterize EACH of the three given statements as being TRUE or FALSE and then indicate the collective true-false status of the statements using the choices:
a) All three statements are true.
b) Two of the three statements are true.
c) Only one of the statements is true.
d) None of the statements is true.
(1) The active site of an enzyme always contains one or more metal atoms.
(2) The water-soluble vitamins are the B vitamins and vitamins A and C.
(3) An enzyme’s turnover number is the rate at which it is degraded and resynthesized within the human body.
a.All three statements are true.
b.Two of the three statements are true.
c.Only one of the statements is true.
d.None of the statements is true.
37.Statements:
(1) An apoenzyme, by itself, has no biochemical activity.
(2) Urease is an example of an enzyme with absolute specificity.
(3) All enzymes have names that end in -ase.
a.All three statements are true.
b.Two of the three statements are true.
c.Only one of the statements is true.
d.None of the statements is true.
38.Statements:
(1) The primary function of vitamin D in the body is that of an antioxidant.
(2) Holoenzymes are conjugated enzymes.
(3) An increase in enzyme activity is always associated with an increase in the temperature of an enzyme-containing system.
a.All three statements are true.
b.Two of the three statements are true.
c.Only one of the statements is true.
d.None of the statements is true.
39.Statements:
(1) Activation of a zymogen produces a proteolytic enzyme.
(2) An enzyme-substrate complex is the final product in most enzyme-catalyzed reactions.
(3) Three forms of vitamin A are active in the human body.
a.All three statements are true.
b.Two of the three statements are true.
c.Only one of the statements is true.
d.None of the statements is true.
(1) A substrate is the substance upon which an enzyme “acts.”
(2) Competitive enzyme inhibition is a reversible process.
(3) Vitamin C is necessary for the formation of the structural protein collagen.
a.All three statements are true.
b.Two of the three statements are true.
c.Only one of the statements is true.
d.None of the statements is true.
41.Statements:
(1) The enzyme lactase catalyzes the hydrolysis of lactose.
(2) The spent form of vitamin E is regenerated by vitamin C.
(3) All coenzymes are cofactors but not all cofactors are coenzymes.
a.All three statements are true.
b.Two of the three statements are true.
c.Only one of the statements is true.
d.None of the statements is true.
42.Statements:
(1) Enzymes undergo all of the reactions of proteins including denaturation.
(2) Vitamin E, a cholesterol derivative, can be synthesized in the skin by sunlight irradiation.
(3) The optimum pH for enzyme activity within the human body is always within the physiological pH range of 7.0 to 7.5.
a.All three statements are true.
b.Two of the three statements are true.
c.Only one of the statements is true.
d.None of the statements is true.
43.Statements:
(1) All of the B vitamins are water-soluble.
(2) The induced-fit model for enzyme action allows for small changes in active-site geometry.
(3) Noncompetitive enzyme inhibitors bind to an enzyme at sites other than the active site.
a.All three statements are true.
b.Two of the three statements are true.
c.Only one of the statements is true.
d.None of the statements is true.
44.Statements:
(1) The B vitamins serve as precursors for enzyme cofactors.
(2) Associated with allosteric enzyme action are substances known as regulators.
(3) Kinases belong to the class of enzymes called isomerases.
a.All three statements are true.
b.Two of the three statements are true.
c.Only one of the statements is true.
d.None of the statements is true.
45.Statements:
(1) The process of enzymatic browning requires the presence of oxygen.
(2) The mode of action of penicillin drugs is selective competitive reversible inhibition.
(3) Bergamottin exerts its effect on enzymes by a process called suicide inactivation.
a.all three statements are true
b.two of the three statements are true
c.only one of the statements is true
d.none of the statements is true
