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Most enzymes are proteins or glycoproteins. However, some enzymes, presumably the oldest ones, are

1.Most enzymes are proteins or glycoproteins. However, some enzymes, presumably the oldest ones, are
a. lipids
b. carbohydrates
c. ribonuclic acids
d. deoxyribonucleic acids
2.An enzyme that converted glucose to frutose would be called
a. an isomerase
b. a transferase
c. a lyase
d. a hydolase
3.Vitamin B2 (riboflavin) is part of a complex enzyme system. The vitamin B2 part is called the
a. cofactor
b. coenzyme
c. apoenzyme
d. proenzyme
4.The protien portion of an enzyme is referred to as the
a. prosthetic group
b. apoenzyme
c. cofactor
d. ribozyme
5.The active site of an enzyme
a. is frequently located in a cleft in the enzyme
b. is the portion of the enzyme to which the substrate binds
c. contains the reactive groups that catalyze the reaction
d. all the above
6.A noncompetitive inhibitor
a. binds to the active site of an enzyme
b. increases the rate of enzyme action
c. alters the primary structure of the enzyme
d. none of these
7.A competitive inhibitor
a. binds to the active site of an enzyme
b. slows the reaction down at low substrate concentrations
c. has little effect on the reaction at very high substrate concentration
d. all of the above
8.The rate of an enzyme-catalyzed reaction is always directly proportional to the
a. substrate concentration
b. square of the substrate concentration
c. reciprocal of the substrate concentration
d. amount of enzyme present
9.Food preservation is often acheived by enzyme inhibition. Pickles are preserved is storage by
a. increasing the temperature
b. decreasing the temperature
c. increasing pH
d. decreasing pH
10.In the lock and key model of substrate binding enzymes
a. the substrate changes its conformation to fit the active site
b. the active site changes its conformation to fit the substrate
c. the active site is rigid and the substrate must fit exactly
d. the substrate binds only to part of the active site
11.In the induced-fit model of substrate binding
a. the substrate changes its conformation to fit the active site
b. the sctive site stays the same, but the rest of the enzyme changes when substrate binds
c. there is a conformation change in the enzyme active site when the substrate binds
d. there is aggregation of several enzyme molecules when the substrate binds
12.At very high substrate levels the maximum rate is achieved when
a. no inhibitor is present
b. a competitive inhibitor is present
c. a noncompetitive inhibitor is present
d. either a or b
13.The fundamental difference between competitive and noncompetitve inhibition is
a. the degree of cooperativity
b. the size of the active site of the enzyme
c. the manner of binding of substrate to the enzyme
d. the manner of binding inhibitor to the enzyme
14.Which mode of enzyme control is affected by a regulator
a. feedback control
b. activation of a proenzyme
c. selection of an isoenzyme
d. allosterism
15.Which protease enzyme is used in meat tenderizers
a. papain
b. pepsin
c. trypsin
d. chymotrypsin
16.Sulfa drugs kill microorganisms because they inhibit folic acid synthesis
a. by competitive inhibition
b. by noncompetitive inhibition
c. by denaturing the enzyme
d. by interacting with the natural substrate, para-aminobenzic acid
17.The receptors on the surfaces of cell membranes are
a. lipids
b. carbohydrates
c. proteins
d. nucleic acids
18.Curare, the poison of Amazon Indians, can cause death by permanently relaxing muscles. Curare works this way because it is
a. a noncompetitive inhibitor of the enzyme that synthesizes acetylcholine
b.a competitive inhibitor of the enzyme that synthesizes acetylcholine
c. an inhibitor of acetylcholinestrease
d.a noncompetitive inhibitor of phosphodieterase
19.Alzheimer's disease affects nerve transmission because
a. it causes acetylcholine to not be released from its storage
b. it causes the synthesis of acetylcholine to be impaired
c. it causes the demyelination of the neuron membrane
d. it produces a protein that blocks the ligand-gated ion channel
20.The neurotransmitter histamine is
a. cholinergic
b. adrenergic
c. peptidergic
d. nicotinergic
21. Peptidergic neurotransmitters
a. are extremely rare, with only a couple of examples currently known
b. are all based on a pentapeptide structure
c. have a wide variety of functions in the brain, including perception of pain and hunger
d. are the same as cholinergic neurotransmitters
23. Steroid hormones
a. all act at the cell membrane by binding to a receptor
b. all act inside of the cell after passing through an active transport protein
c. act slowly when they must penetrate the cell membrane and affect RNA transcription, but can act more quickly in some cases when they bind to membrane receptors
d. act mor quickly than a cAMP mediated cascade
23.Insulin's mode of action
a. affects the synthesis of an enzyme
b. activates one or more enzymes
c. affects transcription of a gene
d. affects the permeability of membranes
24. The drug Cognex seems to improve the memory of patients with Alzheimer's disease. It is a potent inhibitor of
a. acetylcholine
b. B-amyloid protein
c. acetylcholinesterace
d. release of K+ from vesicles
25. Which of the following is NOT true concerning Alzheimer's disease
a. patients often have plaques in their brain's nervous tissue formed by the B-amyloid
b. there is, as yet, no cure for the disease
c.patients usually have diminished levels of acetylcholine
d. drugs that mimic the action of acetylcholinesterase have been proven to help Alzheimer's patients
26. Nerve gases such as Sarin are
a. phosphonates
b. phosphates
d. dihydrogenphosphates
27.The compound in red wine that causes hangover headaches is
a. tyramine
b. monosodium glutamate
c. nitroglycerine
d. phenylethylamine
28. Insulin-dependent diabetic patients
a. do not have enough insulin receptors on their cells
b. may have a defect in the pancreas, which manufactures insulin
c. have lower than normal glucose levels in the blood
d. all of these
29. Which of the following is true about diabetics
a. insulin-dependent diabetics usually starts after age 40
b. non-insulin dependent diabetics is caused by having too few insulin receptors on the cells
c. Orinase and Diabinese can help insulin-dependent diabetics, but not the non-insulin dependent ones
d. none of the above is true