Chem 103 exam 4 Flashcards
Which usually forms a covalent bond with an amino acids’ side chain in the active site of the enzyme?
A) competitive reversible inhibition
B) non-competitive reversible inhibition
C) irreversible inhibition
D) not an inhibition
Irreversible inhibition
Which inhibition can be reversed by adding excess of the substrate?
A) competitive reversible inhibition
B) non-competitive reversible inhibition
C) irreversible inhibition
D) not an inhibition
Competitive reversible inhibition
In which inhibition does the inhibitor resemble the substrate?
A) competitive reversible inhibition
B) non-competitive reversible inhibition
C) irreversible inhibition
D) not an inhibition
Competitive reversible inhibition
Inhibitor binds to enzyme at different site than substrate, but it can be removed
A) competitive reversible inhibition
B) non-competitive reversible inhibition
C) irreversible inhibition
D) not an inhibition
non-competitive inhibitor
An example is ethanol as an antidote for methanol poisoning
A) competitive reversible inhibition
B) non-competitive reversible inhibition
C) irreversible inhibition
D) not an inhibition
Competitive reversible inhibition
Allosteric enzyme inhibitors are examples of what type of inhibition?
A) competitive reversible inhibition
B) non-competitive reversible inhibition
C) irreversible inhibition
D) not an inhibition
non-competitive reversible inhibition
Question #7 on exam 4
D) graph I = Temp, graph II = substrate conc., graph III = enzyme conc.
Which pairing is NOT correct?
A) kinase - transferase
B) decarboxylase - ligase
C) mutase - isomerase
D) synthetase - ligase
E) All answers are correct
B) decarboxylase - ligase
Which is true of pepsin?
A) It is a peptidase
B) Its optimum pH range is the same as most enzymes
C) Stomach acid catalyzes the conversion of pepsinogen to pepsin
D) all are true
E) A and C
E) A and C;
A) It is a peptidase
C) Stomach acid catalyzes the conversion of pepsinogen to pepsin
What type of enzyme would be synthesized first as a zymogen?
A) carbohydrate digesting enzymes
B) protein digesting enzymes
C) blood clotting enzymes
D) A, B, and C
E) B and C
E) B and C
B) protein digesting enzymes
C) blood clotting enzymes
What factors affect the activity OF ALL ENZYMES?
A) substrate saturation
B) genetic control to increase the concentration of the enzyme
C) temperature
D) A,B, and C
E) A and B
D) A,B, and C
A) substrate saturation
B) genetic control to increase the concentration of the enzyme
C) temperature
What type of bond can hold a substrate to the active site of an enzyme?
A) amide bond
B) disulfide bond
C) salt bridge
D) A,B, and C
E) A and B
C) salt bridge
Which is true of cofactors?
A) without it’s cofactor the enzyme is not
active.
B) Many coenzymes are made from vitamins
C) Cofactors can be metal ions
D) A, B and C
E) A and B
D) A, B and C
A) without it’s cofactor the enzyme is not
active.
B) Many coenzymes are made from vitamins
C) Cofactors can be metal ions
which of the following has physiological activity (without adding any other group ) ?
A) holoenzyme
B) apoenzyme
C) proenzyme
D) coenzyme
E) A and B
A) holoenzyme
Which is true of a Zymogen ?
A) It’s other name is proenzyme
B) It is synthesized with more amino acids than the active enzyme
C) Its active site is block by several amino acids
D) A, B and C
E) A and B
D) A, B and C
A ) It’s other name is proenzyme
B) It is synthesized with more amino acids than the active enzyme
C) Its active site is block by several amino acids.
which is true about denaturing an enzyme ?
A) Severe pH changes will cause permanant denaturing
B) Severe temperature changes will cause permanant denaturing
C) Heavy metals can denature an
enzyme
D) A, B and C
E) A and C
E) A and C
A) Severe pH changes will cause permanant denaturing
C) Heary metals can denature an enzyme
which is true about denaturing an enzyme?
A) The primary structure is usually effected by denaturing
B) Denaturing is ALWAYS Permanant
C) Denaturing affects globular proteins more than fibrous proteins
D) A, B and C,
E ) A and B
C) Denaturing affects globular proteins more than fibrous proteins
which of the following statements are
true concerning enzymes versus hormones?
A) Enzymes and hormones are all proteins
B) No hormone can enter a cell directly
C) Enzymes are used in the cells where they are made
D) A, B and C
E) A and C
C) Enzymes are used in the cells where
they are made
which is true concerning Trypsinogen and Tripsin?
A) Trypsin is a protein while trypsinogen is not
B) Trypsin is a larger protein than Trypsinogen
C) Trypsin has catalytic ability while Trypsinogen does not
D) Both catalytic ability but not for the same Substrate
E) B and D
C) Trypsin has catalytic ability while trypsinogen does not
Which is true of blood clotting mechanism?
A) Blood senum has fibrinogen while blood plasma does not
B) The actual clot is a protein called fibrin
C) plasminogen is the active enzyme that will destroy the clot when not needed
D)A and B
E) B and C
B) The actual clot is a protein called fibrin
What is true of acetylcholine?
A) It contains an ester linkage
B) It is a neurotransmiter
C) A molecule that blocks its receptor site can be used as a muscle relaxant
D) A, B and C
E) A and B
D) A, B and C
A) It contains an ester linkage
B) It is a neurotransmiter
C) A molecule that blocks its receptor site can be used as a muscle relaxant
Which is true of acetylcholinesterase?
A) It can convert millions of substrate molecules to product within minutes
B) If permanently inhibited, it can cause over stimulation of muscles, convulsions and death
C) It synthesizes acetylcholine from acetic acid and choline
D) A, B and C
E) A and B
E) A and B
A) It can convert millions of substrate molecules to product within minutes
B) If permanently inhibited, it can cause over stimulation of muscles, convulsions and death
Which is true of digestion?
A) lt is done at the cellular level
B) It is mainly oxidation reactions
C) It is mainly hydrolysis reactions
D) A and B
E) A and C
C) It is mainly hydrolysis reactions
Which of the following is not stored?
A) amino acids
B) triglycerides
C) glucose
D) A and B
E) No answer is correct
A) amino acids
Which product of digestion does not need a protein channel to get into the blood?
A) Glucose
B) Amino Acids
C) Glycerol
D) Fatty Acids
E) C and D
D) Fatty Acids
Which is true of glycerol?
A) It is produced from the digestion of triglyerides
B) It is soluble in blood
C) All cells can use it for energy
D) A, B and C
E) A and B
D) A, B and C
A) It is produced from the digestion of triglyerides
B) It is soluble in blood
C) All cells can use it for energy
Which product of digestion is not soluble in blood?
A) Glucose
B) amino acids
C) fatty acids
D) B and C
E) no answer is correct
C) fatty acids
Which is true of diabetes?
A) In some cases the pancreas does not synthesize enough insulin
B) In some cases there is a lack of receptor sites for the insulin molecule on the target cells
C) All diabetics need insulin shots
D) A, B and C
E) A and B
E) A and B
A) In some cases the pancreas does not synthesize enough insulin
B) In some cases there is a lack of receptor sites for the insulin molecule on the target cells
Which is true of insulin?
A) It is a protein
B) It needs a protein channel to get into the cell
C) too much insulin can cause insulin shock D) A, B and C
E) A and C
E) A and C
A) It is a protein
C) too much insulin can cause insulin shock
Which is true of glycogenolysis?
A) It is done in the liver and muscle
B) The enzyme glycogen phosphorylase catalyzes the reaction
C) Activated by insulin
D) A, B and C
E) A and B
E) A and B
A) It is done in the liver and muscle
B) The enzyme glycogen phosphorylase catalyzes the reaction
Which is true of gluconeogenesis?
A) Done only in the liver
B) Activated by glucagon
C) It is inhibited by insulin
D) A, B and C
E) B and C
D) A, B and C
A) Done only in the liver
B) Activated by glucagon
C) It is inhibited by insulin
What are the possible starting materials for gluconeogenesis
A) All amino acids
B) lactic acid
C) glycerol
D) A, B and C
E) B and C
E) B and C
B) lactic acid
C) glycerol
Which is true of glucagon?
A) It is protein hormone
B) It activates the hydrolysis of glycogen in liver and muscle
C) It can slide through a protein channel
D) A and B
E) A, B and C
A) It is protein hormone
Which processes are activated by insulin?
A) gluconeogenesis
B) glycogenolysis
C) fatty acid synthesis
D) B and C
E) no answer is correct
C) fatty acid synthesis
Which cells need insulin to facilitate glucose entry?
A) muscle cells
B) kidney cells
C) brain cells
D) A, B and C
E) A and B
A) muscle cells
What processes are stimulated by epinephrine?
A) glycogenolysis in the liver
B) glycogen is converted to glucose-1-phosphate in the muscles
C) Gluconeogenesis in the liver
D) A and B
E) A, B and C
E) A, B and C
A) glycogenolysis in the liver
B) glycogen is converted to glucose-1-phosphate in the muscles
C) Gluconeogenesis in the liver
Which is true of the enzyme glycogen synthetase?
A) found only in the liver
B) found in liver and muscle
C) found in only the muscle
D) activated when blood sugar is high
E) B and D
E) B and D
B) found in liver and muscle
D) activated when blood sugar is high
What happens when glucagon affects a liver cell?
A) It has no affect
B) Glucagon enters the cell through protein channels
C) Glucagon sits on the outside of the liver cell membrane and turns on the cAMP system
D) B and C
E) no answer is correct
C) Glucagon sits on the outside of the liver cell membrane and turns on the cAMP system
Muscle cells have no receptor sites for which hormone?
A) Glucagon
B) Insulin
C) epinephrine
D) A and B
E) A and C
A) Glucagon
What hormone will stimulate glycogenolysis in muscle?
A) glucagon
B) insulin
C) epinephrine
D) A and C
E) no answer is correct
C) epinephrine
Which is true of the conversion of glucose-1-phosphate to glycogen?
A) The energy needed to synthesize the glycogen comes from breaking the high energy phosphate bond on glucose
B) It is done in all cells
C) It is done when blood sugar is low
D) A and B
E) no answer is correct
A) The energy needed to synthesize the glycogen comes from breaking the high energy phosphate bond on glucose
Which of the following can get out of a cell using a protein channel?
A) glycogen
B) glucose
C) glucose-1-phosphate
D) A, B and C
E) A and B
B) glucose