Digestion Enzyme Practice Test (3)

8/17/2019 Digestion Enzyme Practice Test (3)

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ENZ YMESC 1. Enzymes function to increase the rate of a metabolic reaction by A. denaturing the substrate. B. adding energy to the reaction. C. decreasing the energy of

activation. D. increasing the concentration of the reactants.

D 2. An enzyme speeds up a chemical reaction by A. regulating pH. B. acting as a buffer. C. preventing denaturation. D. loering the energy of activation.

C !. "he role of an enzyme in a chemical reaction is to A. emulsify fats. B. prevent denaturation. C. speed up the reaction. D. buffer any acids or bases.

B #. Enzymes often A. absorb fatty acids. B. help in hydrolysis reactions. C. serve as a long term source of energy. D. serve as the structural frameor$ of cell alls.

B %. &n the cell' enzymes act as A. buffers. B. catalysts. C. neurotransmitters. D. emulsifying agents.

C (. Enzymes consist of chains of A. fatty acids. B. nucleotides. C. amino acids. D. carbohydrates.

C ). Compounds that are needed for enzymes to function properly are A. buffers. B. steroids. C. vitamins. D. heavy metals.

B *. A non+protein molecule that aids the action of an enzyme to hich it is loosely bound is called a,n- A. initiator. B. coenzyme. C. competitive inhibitor. D. enzyme+substrate comple.

C /. "he area of an enzyme into hich a substrate fits is called the A. catalyst. B. product. C. active site. D. activated comple.C 10. "he molecule that fits into the enzymes active site is the A. codon. B. vitamin. C. substrate. D. coenzyme.

B 11. "he active site of an enzyme is A. formed by the substrate. B. altered by heavy metals. C. altered by the substrate concentration. D. destroyed during itsreaction ith a substrate.

A 12. High concentrations of thyroin in the blood ill cause metabolic reactions in a cell to A. speed up. B. slo don. C. stop occurring. D. remain unchanged.

C 1!. hy ould drugs li$e penicillin destroy bacteria but have no effect on human cells3 A. Human enzymes ould be denatured by penicillin. B. Bacterial cells oulduse penicillin as a coenzyme. C. 4enicillin ould fit the active site of bacterial enzymes. D. Enzymes in human cells ould use penicillin to produce ecessenergy.

B 1#. "hyroin treatment can be used to stimulate eight loss in some people ith an endocrine deficiency. "his treatment ill A. cause a loss of appetite. B. increasethe metabolic rate. C. prevent the conversion of fatty acids to fat. D. accelerate the conversion of glucose to glycogen.

B 1%. "he pituitary gland secretes a hormone into the bloodstream hich stimulates the production of thyroin. &n turn' production of thyroin is inhibited by A. the effectof thyroin on the adrenal gland. B. the effect of thyroin on the pituitary gland. C. decreasing the amount of calcium in the diet. D. increasing the amount ofiodine in the blood.

B 1(. "he tertiary structure of an enzyme is A. its helical orientation in space. B. its three+dimensional' globular shape. C. the particular se5uence of amino acids. D.the arrangement of several proteins to create a functional unit.

B 1). A reaction catalyzed by a human enzyme as carried out at 206C. &f there is an ecess of substrate' hich of the folloing ould cause the greatest increase inthe rate of the reaction3 A. 7oering the temperature to 106C. B. Adding more enzyme and raising the temperature to !06C. C. Adding more substrate andraising the temperature to !06C. D. Adding more enzyme and loering the temperature to 106C.

DIGEST ION & HUMAN ORG ANIZ ATIOND 1. Digestion is defined as the process hereby A. glucose is converted to glycogen. B. carbon dioide is reduced to carbohydrate. C. proteins are absorbed into the

bloodstream. D. food is chemically and physically bro$en don.

D 2. hich of the folloing describes peristalsis3 A. the physical brea$don of fats B. production of vitamins by E. coli C. release of enzymes by the pancreas D.muscle contractions of the digestive tract

D !. A patient complains of a burning sensation in the chest. "his as found to be caused by gastric 8uice in the esophagus. "he structure most likely not functioningproperly is the A. pharyn. B. epiglottis. C. pyloric sphincter. D. cardiac sphincter.

B #. Cheing food aids digestion by A. stimulating the release of bile. B. increasing the surface area of the food. C. brea$ing up large protein molecules into peptides.D. completing the chemical brea$don of carbohydrates.

C %. "he purpose of physical digestion is to A. hydrolyze large molecules. B. increase the amount of feces. C. increase the surface area of food. D. slo the action ofdigestive enzymes.

C (. "he purpose of physical digestion is to A. hydrolyze large molecules. B. increase the amount of feces. C. increase the surface area of food. D. slo the action ofdigestive enzymes.

C ). hich of the folloing structures prevents food from entering the trachea3 A. 7aryn. B. 4haryn. C. Epiglottis. D. Cardiac sphincter.A *. "he part of the digestive tract here starch first undergoes chemical digestion is the A. mouth. B. stomach. C. large intestine. D. small intestine.

B /. 9aliva contains an enzyme that partially digests A. fat. B. starch. C. protein. D. nucleic acids.

B 10. Eating hich of the folloing ould slo the rate of chemical digestion in the mouth3 A. Cheese. B. &ce cream. C. 4otato chips. D. Bread ith butter.

B 11. hich of the folloing is re5uired to convert pepsinogen into pepsin3 A. :ucus secretions. B. Hydrochloric acid. C. 9odium bicarbonate. D. 7ipid in the stomach.

A 12. A role of hydrochloric acid in the stomach is to A. $ill bacteria. B. hydrolyze fat. C. digest protein. D. activate trypsin.

C 1!. 9odium bicarbonate , ;aHC

A 1#. hich of the folloing ould inhibit trypsins ability to form an enzyme+substrate comple3 A. pH of !. B. "emperature of ! C. C. &ncreased bileproduction. D. Decreased numbers of villi.

B 1%. hich of the folloing is not a function of pancreatic 8uice3 A. =aising pH. B. Emulsifying. C. 9tarch digestion. D. 4rotein digestion.

D 1(. hich of the folloing is a function of pancreatic 8uice3 A. loering pH. B. Emulsifying. C. fat digestion. D. 4rotein absorption.

D 1). &f sodium bicarbonate ,;aHC


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C !0. hich of the folloing is an eample of physical digestion3 A. Hydrolysis. B. =elease of gastrin. C. Churning in the stomach. D. Action of lipase in the smallintestine.

C !1. "he presence of large numbers of mitochondria in the cells lining the small intestine allos it to A. release HCl. B. produce bile. C. absorb glucose. D. synthesizevitamins.

D !2. hich of the folloing enzymes is correctly matched ith its source3 A. Amylase > stomach. B. 4eptidase > pancreas. C. "rypsin > small intestine. D. :altase >small intestine.

A !!. 9tructures of the small intestine that aid in the absorption of nutrients include A. villi. B. cilia. C. E. Col i. D. sphincters.

A !#. High levels of toins in the blood may indicate a problem ith the function of the A. liver. B. stomach. C. pancreas. D. small intestine.

A !%. "he liver plays vital roles in all of the folloing systems except the A. nervous system. B. digestive system. C. ecretory system. D. circulatory system.

B !(. @itamins and amino acids are produced in the large intestine by A. feces. B. bacteria. C. the cells of the villi. D. the reabsorption of ater.

B !). A function of the liver is to A. produce glucagon. B. brea$ don blood cells. C. regulate sodium and potassium levels. D. secrete enzymes into the smallintestine.

C !*. 4roducts of the liver include A. pepsin' gastrin and bile. B. bile' proteases and urea. C. bile' urea and blood proteins. D. proteases' amylases and lipase.

B !/. &f a persons liver fails' hich process listed belo ould stop3 A. Digestion of proteins. B. Destruction of red blood cells. C. 9torage of starch beteen meals. D.=eabsorption of ater from the digestive tract.

B #0. "he emulsification of fats is a result of the release of secretions from the A. pancreas. B. gall bladder. C. small intestine. D. salivary glands.

A #1. "he emulsification of fat is carried out by A. bile. B. lipase. C. pepsin. D. bicarbonate ions.

A #2. Bile causes the emulsification of A. lipids. B. proteins. C. nucleic acids. D. carbohydrates.

A #!. 4eople ho have their gall bladder removed have the most difficulty digesting A. butter. B. apples. C. vitamins. D. egg hites.

A ##. "he gall bladder functions to A. store bile. B. digest fats. C. store urine. D. release sodium bicarbonate.

A #%. Emulsification of fat is the function of A. bile. B. lipase. C. pepsin. D. sodium bicarbonate ,;aHC

A #(. =emoval of the gall bladder ould affect a persons ability to digest A. lipids. B. sugars. C. proteins. D. carbohydrates.

B #). "he release of cholecysto$inin ,CC- ould most likely be triggered after a meal of A. fruit. B. meat. C. bread. D. lettuce.

C #*.

C )(. Bread that has been partially digested by saliva tends to have a seet taste. hich enzyme and substrate are involved3 A. 4epsin and starch. B. 4epsin andprotein. C. Amylase and starch. D. Amylase and protein.

C )). "he digestion of starch is catalyzed by a polymer made up of A. fatty acids. B. nucleotides. C. amino acids. D. monosaccharides.


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4/15

43. A

44. A

45. A

46. A

47. B

48. C

49. A

50. C

51. D

52. B

53. C

54. A

55. B56. D

57. A

58. D

59. B

60. B

61. A

62. B

63. C

64. A

65. A

66. D

67. D

68. C

69. B

70. B

71. B

72. B

73. A

74. D

75. D

76. C

77. C

78. B

79. D

80. A

81. A

82. C

83. C

84. B

ENZ YMES

1. An experiment was conducted to measure the effect of temperature on an enzyme isolated fromthe small intestine. Data was collected and graphed asshown below.

Explain why the following temperatures change theactivity rate of the enzyme.

O °C to ! °C (1 mark)

! °C (1 mark)

"! °C to #! °C (2 marks)

$.

%dentify & in the above diagram' as well as all the other parts of this enzyme(catalyzed reaction.


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.)he arrow labelled X in the graph above indicates the

A. net energy gain. *. activation energy. C.temperature of the products. D. temperature of thereactants.

".

)he structure labelled X in the diagram is a+n, A. enzyme. *. substrate. C. coenzyme. D. enzyme(substrate complex.

#. )he structure labelled X in thereaction above is

A. a vitamin.*. the substrate.C. the active site.D. a competitive inhibitor.

-. a, Explain the loc/ and /ey0 model of enzymatic action. (2 marks)b, Explain how denaturation stops enzymatic action. (1 mark)

.)he two digestive enzymes shown in the graphhave the same substrate. 2hat would thesubstrate be3

A. 4tarch. *. 5rotein. C. 6altose. D. 5eptides.

7. Draw a labeled diagram to illustrate the loc/ and /ey0 model of enzymatic action. (4 marks)8. )he following graph shows an enzyme catalyzed reaction.

2hich of the following might explain the change in the rate ofreaction at temperatures greater

than #! °C

A. 6ore enzyme was added. *. 6ore substrate was added. C.Coenzymes compete for the enzyme9s active site. D. )he tertiaryshape of the enzyme has been altered.


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1!. )he following data show the rate of an enzyme(catalyzed reaction at various temperatures.

a, :raph the data on the grid provided. (1mark)

b, ;se the graphed data to describe the effectof temperature on the rate of enzymeactivity. (4 marks)

11. An experiment investigating enzyme activity was carried out. A test tube was prepared containingsubstrate solution W and enzyme solutions 1 and $.

• )he reactions that occur in the test tube are summarized below<

• )he letters represent substrates and products and the numbers represent enzymes.

a, 4tate tw ways to increase the rate of production of product =. (2 marks)b, A substance is added to the test tube containing substrate 2. As a result' no product is formed.4uggest what this substance may be and explain how it achieves these results. (2 marks)

1$. Describe the effect that the following would have on enzyme action< +7 mar/s,a, temperature b, p> c, substrate concentration d, competitive inhibitors

1. Explain how the following changes affect an enzyme(catalyzed reaction<a, the p> is changed from to 7 +$ mar/s,b, the temperature is increased from $! ? C to ! ? C +$ mar/s,c, a competitive inhibitor is added +$ mar/s,

1". a, Explain the change in reaction rate for the graph +$ mar/s,

4;*4)@A)E COCE)@A)%O

@ E A C ) % O @ A ) E

b, %dentify and explain how three other factors could decrease thereaction rate of the enzyme(catalyzed reaction. Bor each factor give reasons to support your answer.+- mar/s,

1#. %n the cell' enzymes act as A. buffers. *. catalysts. C. neurotransmitters. D. emulsifying agents.


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DIGEST I!E SYST EM1. abel the parts on the diagram and give one function for each during

the digestion of a "rt#$%.

$.4ecretions from which of the following would have the effectshown in the diagram3

A. liver *. mouth C. stomach D. large intestine

.

". )he to the left is found lining the walls of the A. colon. *. stomach. C. esophagus. D. small intestine.

abel the following on this drawing< lacteal' capillary networ/' columnar cells'interstitial gland


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#.

-.2hich organ releases an enzyme that digests fats3

A. 2 *. & C. = D. 2hich organ functions to /ill bacteria' store food and digestprotein3

A. 2 *. & C. = D.

. %n the following reaction' product X could be a+n,& = lipase fat > $ O

A. peptide. *. fatty acid. C. nucleotide. D. amino acid.


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7.

8. :raph 1 represents the rateof reaction between lipaseand its substrate. %n graph $'whatoccurred at time X thatcaused the change in thereaction3

A. Bat was added. *. )hep> was changed from # to7. C. A competitive inhibitor was added. D. )hetemperature of the reaction was raised to 1!!F C.


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1!.

a, )he diagrams illustrate a reaction that occurs in the small intestine. :ive the specific namefor each of the following. ( 6olecule &< (1 mark) ( 6olecule =< (1 mark)b, %n a laboratory experiment' substance Y was added in increasing amounts until it eventuallyhad no effect on the rate of the reaction. Explain why. (1 mark)c, A solution containing lead ions was added to the reaction. >ow will the addition of thissolution affect the reaction3 Explain why. (2 marks)

11. 2hich of the following substances is absorbed into the structure labelled X 3 A. Bat. *. ;rea. C. :lucose. D. Amino acids.

1$. )he reaction shown below is catalyzed by secretions from which organs3protein >$O peptides

A. pancreas and liver *. liver and duodenum C. stomach and pancreas D. duodenum and stomach

1.

a, 4tate tw functions of structure . (2 marks)b, Bor each of the following structures' list %# enzyme it secretes andthe substrate thatthe enzyme acts upon. (4 marks 1 mark #a' r #%*+m#, 1 mark#a' r s-.strat#)


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1". Complete the following table for the digestive system. (4 marks 1/2 mark #a')

1#. Complete the table below by giving %# #%*+m# "r0-'#0 by each of the following glandsand by stating the 0$#st$# "r0-'t of that enzyme. (3 marks 1 mark #a')

1-. a, )he brea/down of some poisonous substances found in the bloodoccurs in organ

A. 2 *. & C. = D.

b, Amylase is synthesized at the

A. nucleus. *. ribosome. C. lysosome. D. mitochondrion.

c, A role of water in cells of the human body is to A. emulsify fats. *. act as a solvent. C. act as an enzyme. D.denature proteins.

d, 2hich of the following is composed of nucleotides3 A. Bat. *. @A. C. 4tarch. D. 5rotein.

e, 2hich of the following is a polymer3 A. A)5. *. :lucose. C. :lycerol. D. Cellulose.


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1. An experiment was conducted to determine the effectsof p> on pepsin. )he following stepswere performed<1. Bive test tubes were numbered and eGual amountsof egg white and water were added to each.$. A buffer was added to each test tube to maintain itsp> at the level given inthe table below.. An eGual amount of pepsin was added to each testtube.

After one hour' the mass of egg white r#ma$%$% in each test tube was determined. )he resultsare recorded below<

a, Draw a graph that compares the p> to the amount of egg white remaining in each test tube.abel the x(axis +horizontal axis, as p>. (2 marks)

b, 2hat appears to be the optimum p> for pepsin3 (1 mark)

c, Explain what happens to pepsin at a p> of ' and why this affects its activity. (2 marks)17. Describe how the small intestine is specialized for digestion and absorption.

Digestion< (2 marks)

• Absorption< (2 marks)

18. a, ame the tr## glands that secrete enzymes that digest carbohydrates. ( marks)b, ame the structure in the small intestine that absorbs the products of carbohydratedigestion. (1 mark)c, 2here does the body store the excess products of carbohydrate digestion3 (1 mark)

$!. 2hich of the following would be produced in areaction catalyzed by enzymes /nown asnucleases3

$1. %n paragraph form' describe the chemical brea/down of starch to a monosaccharide in thehuman body. (5 marks)

$$. a, ame the components of pancreatic Huice and state how each aids in the digestionof food. (4 marks)b, 2hat is the function of water in pancreatic Huice3 (1 mark)


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$.Digested polysaccharides are ta/en in by cells in the presence of a hormone secreted from the glandlabelled

A. 2*. &C. =D.

$". %n the diagram below' amino acids are transported into structure A. 2. *. &.C. =. D. .

$#. Complete the following table summarizing digestive enzyme activity.(4 marks 1/2 mark #a')

$-. Describe the mechanisms involved in the digestion and absorption of fat. (4 marks)

$. )he concentration of glucose in the blood was recordedover a set period of time andthe following pattern was observed.

a, Does the above graph represent positive or negativefeedbac/3 (1 mark)b, Explain the hormonal response when thei, blood glucose concentration is high. (2 marks)ii, blood glucose concentration is low. (2 marks)


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$7. %n an experiment' three different pancreatic enzymes were placed in separate test tubes. )emperaturewas maintained at F C. Iegetable oil' egg white and starch were added to each test tube and thecontents were analyzed after ! minutes.a, )est tube A was found to contain glycerol and fatty acids. 2hat was the enzyme added3(1 mark)b, )est tube * contained trypsin. 2hich product of digestion would it contain3 (1 mark)c, )est tube C was found to contain a disaccharide. %dentify the enzyme and product of digestioncontained in test tube C. (2 marks)d, 5redict the effect on the speed of the reaction in test tube A if bile were added and give a reason foryour answer. (2 marks)

$8. Describe 4 ways in which surface area is maximized in the digestive system.(4 marks 1 mark #a')

!. )he following procedurewas conducted to observethe effect of p> on the rateof enzyme activity.J 1! m of a starch solutionwas added to each of #lettered test tubes.J A different p> buffer wasadded to each tube resultingin the p> shown in thetable below.J An eGual amount of a starch(digesting enzyme was added to each tube.

J Bresh samples were ta/en from #a' t-.# ##r+ m$%-t# and tested with %K%' an indicator that turns from yellow to blac/ when mixed with starch.@esults are recorded in the table below<

a, 2hat do the results indicate is present in a66 the test tubes at one minute3 (1 mark)b, 2hat new substance is present in test tube X at three minutes3 (1 mark)c, 2hich test tube has the optimal p> for the enzyme3 Explain your choice. (2 marks)d, After one hour' a sample from test tube Z still turned blac/. ;sing the loc/ and /ey model of enzymeaction' explain these results. (2 marks)

1. Explain how digestion would be affected if the digestive functions of each of thefollowing organs did %t occur. (3 marks)a, 4alivary glands (1 mark) b, 4tomach (2 marks) c, 5ancreas ( marks)

$. :ive %# role for each of the following in the digestive system. (4 marks 1 mark #a')

a, 5yloric sphincter< b, Iilli< c, 5eristalsis< d, E. coli <. A student set up the experiment illustrated above and /ept it at

o C. After five minutes' the distilledwater in the bea/er was tested and found to contain a sugar but no starch.a, 2hat had occurred inside the tube3 (1 mark)b, 2hat statement can you ma/e about the permeability of themembrane3 (1 mark)c, An identical experiment was set up and /ept at # degreesC. After five minutes' how would the amount of sugar found inthe water differ between the two bea/ers3 Explain your answer. (2 marks)

". Explain the following observations< +$ mar/s each,

a, Bor two cells of eGual volume' it is more effective for a cell that is actively metabolizing to be long andthin rather than short and fat. b, >uman cells' when placed in saturated +#L, salt solution' will die.c, >uman enzymes cannot brea/ down cellulose.

#. 4tate 4%& functions of the liver. + mar/s< M mar/ each,

-. Describe how the removal of each of the following structures would affect the chemical digestion offood< a, salivary glands +1 mar/, b, pancreas +" mar/s,

. ame structures which provide digestive chemicals but through which food does not pass.+ mar/s,


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7.

Complete the table by filling in the blan/ spaces with an appropriate word or phrase. +" mar/s,

8. Describe how each of the following is involved in the chemical digestion of a protein<a, stomach +$ mar/s, b, pancreas + mar/s, c, small intestine +$ mar/s,

"!. 5eople suffering from severe obesity may have part of their small intestine removed or a section of their stomach surgically closed. Brom your /nowledge of digestion' explain the theory behind this type ofsurgery.a, @emoval of a portion of the small intestine +beyond the duodenum, + mar/s,b, 4ection of the stomach surgically closed. +$ mar/s,

"1. A meal high in fats is consumed. Explain the activity of secretin and CCK +cholecysto/inin, and :%5 inthe digestion of fats. +# mar/s,

"$. 2hat is a function of each of the following in the digestive system3 a, peristalsis +1 mar/,b, hydrochloric acid +1 mar/, c, large intestine +1 mar/,

". 2hat effect will the pancreatic duct being bloc/ed have on the normal body functions in humans3+" mar/s,

"". Explain why the following may be considered %%7#ss#%t$a6 organs of the digestive system.+7 mar/s< $ mar/s each, a, stomach b, gall bladder c, large intestine d, mouth

"#. Describe four ways the small intestine is specialized for its function. +" mar/s,

"-. Explain how gastric Huice affects the digestive process in the stomach and small intestine. +- mar/s,

".

Bill in the following table on the digestive system +" mar/s< 1N$ mar/ each,"7. %f an individual were exposed to a liver toxin' such as a weed /iller' the liver would gradually stop

functioning. Even though the liver has stopped functioning' the individual may still live for two or threedays. ;sing five examples explain problems this individual would have' now that the liver is no longerfunctioning. +1! mar/s,

"8. Bour test tubes were placed in a water bath for 1# minutes. )he table below presents the contents' p>'/ind of enzyme' temperature and appearance after 1# minutes.

T-.# 1 T-.# 2 T-.# T-.# 4

8ONTENTS eggwhite water eggwhite eggwhite

"H $ $ $

ENZYME present +unboiled, present +unboiled, present +boiled, present +unboiled,

TEM9ERATURE ##? C ? C 1#? C ? C

A99EARAN8E cloudy cloudy cloudy clear a, %n which tube has digestion ta/en place3 +1 mar/,b, ist and explain the reasons for your choice3 + mar/s,c, 2hich part of the human body produces the enzyme that is responsible for the digestion that isobserved3 +1 mar/,

ENZYME SOURCE OF

ENZYME

SITE OF

ACTIVITY

PRODUCT OF

DIGESTION

pH

salivary glands mouth neutral

pepsin gastric glands peptides

trypsin pancreas alkaline

lipase duodenum fatty acid andglycerol

ORGAN SECRETION pH ENZYME(S)CONTAINED

FOOD ACTED

UPON

mouth saliva

pancreas amylase

lipase

trypsin

gall bladder basic none

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Digestion Enzyme Practice Test (3)