Tuesday, November 13, 2012

carbohydrate



1. Rotation of the plane of polarized light is caused by solutions of all of the following monosaccharides except
a. Glucose
b. Glyceraldehyde
c. Fructose
d. Dihydroxyacetone
e. None of the above

2. Ascorbic acid is an example of
a. Sugar acid
b. Sugar alcohol
c. Sugar phosphate
d. Deoxy-sugar
e. Amino sugar

3. An invert sugar is
a. An equimolar mixture of glucose and fructose
b. An equimolar mixture of a-glucose and 13-glucose
c. An equimolar mixture of a-fructose and 13-fructose
d. The sugar which changes its optical activity from levo- to dextrorotatory
e. None of the above

4. A disaccharide formed of two glucose units is
a. Lactose
b. Maltose
c. Sucrose
d. Amylose
e. Amylopectin

5. Milk sugar is
a. Cellobiose
b. Maltose
c. Sucrose
d. Lactose
e. None of the above

6. Cane sugar is
a. Cellobiose
b. Maltose
c. Sucrose
d. Lactose
e. None of the above

7. Malt sugar is
a. Cellobiose
b. Maltose
c. Sucrose
d. Lactose
e. None of the above

8. Starch is an example of
a. Galactosans
b. Mannosans
c. Glucosaminans
d. Glucosans
e. Fructosans

9. Glycogen is an example of
a. Glucosans
b. Galactosans
c. Mannosans
d. Glucosaminans
e. Fructosans

10. Starch is an example of
a. Structural polysaccharides present in animals
b. Structural polysaccharides present in plants
c. Nutrient polysaccharides present in animals
d. Nutrient polysaccharides present in plants
e. None of the above


11. Which of the following has a free anomeric carbon atom
a. Glucose
b. Mannose
c. Lactose
d. Sucrose
e. Fructose

12. A polysaccharide indigestible by man is
a. Cellobiose
b. Glycogen
c. Amylopectin
d. Cellulose
e. Amylose

13. A branch component of starch is
a. Glucose
b. Amylopectin
c. Amylose
d. Maltose
e. None of the above

14. Which of the following statements characterizes glucose
a. It usually exists in the furanose form
b. It is a ketose
c. Carbon 2 is the anomeric carbon atom
d. It forms part of the disaccharide sucrose
e. It is oxidized to form sorbitol

15. Which of the following contains ketone group
a. Ribulose
b. Glucose
c. Mannose
d. Galactose
e. Lactose

16. Which of the following is non fermentable sugar?
a. Maltose
b. Sucrose
c. Glucose
d. Fructose
e. Lactose

17. Hydrolysis of sucrose yields
a. Two moles of glucose
b. Glucose and fructose
c. Galactose and fructose
d. Glucose and mannose

18. Ribitol is
a. Deoxy sugar
b. Amino sugar
c. Sugar alcohol
d. Sugar acid

19. Inulin is a simple polysaccharide built up of
a. Glucosamine
b. Galactose
c. Fructose
d. Aldose

20. The end products of glycogen hydrolysis by acid is
a. Dextrin
b. Maltose
c. Amylose
d. Glucose

21. The richest site for fructose in the body is
a. Mammary gland
b. Seminal fluid
c. Thyroid gland
d. Prostate


22. D-glucose and D-mannose are epimers with respect to carbon atom number
a. 3
b. 2
c. 5
d. 1

23. Which of the following polysaccharides is not a polymer of glucose
a. Amylose
b. Glycogen
c. Inulin
d. Amylopectin

24. Reduction of glucose produces
a. Mannitol
b. Sorbitol
c. Dulcitol
d. Glucuronic acid

25. Gluconic acid, saccharic acid and glucuronic acid are produced from glucose by
a. Reduction
b. Treatment with acids
c. Oxidation
d. Treatment with bases

26. Galactose is present in the structure of
a. Sucrose
b. Lactose
c. Lecithin
d. Glycogen

27. Which statement is incorrect
a. Glucose and mannose are Epimers
b. α- and β-glucose are Anomers
c. Glucose and galactose are Anomers
d. Ribose and xylose are epimers

28. The invert sugar is
a. Maltose
b. Sucrose
c. Hydrolytic products of sucrose
d. Hydrolytic products of maltose

29. Sorbitol is
a. A sugar alcohol
b. Obtained from glucose
c. Obtained from fructose
d. All of the above

30. By complete acid hydrolysis of starch we obtain
a. Maltose
b. α-glucose
c. β-glucose
d. All of the above

31. The blood sugar is
a. Glucose
b. Fructose
c. Ribose
d. Galactose

32. Ribulose is an example of
a. Aldopentose
b. Ketohexose
c. Ketopentose
d. Deoxy sugar
e. Sugar alcohol

33. Cellulose is
a. Formed of β-glucose
b. Not digested in human intestine
c. A simple polysaccharide
d. All of the above

34. Dextrose is
a. An aldopentose
b. An aldohexose
c. A ketohexose
d. A ketopentose


35. Sorbitol can be obtained from fructose by
a. Oxidation
b. Reduction
c. Hydrolysis
d. Acetylation

36. A reducing disaccharide is
a. Glucose
b. Mannose
c. Maltose
d. Fructose

37. Glucose and mannose are epimers, this means that
a. They are mirror image to each other
b. One is aldose, the other is a ketose
c. They differ only in the configuration to one carbon
d. One is pyranose the other is furanose

38. Starch is
a. A heterogeneous polysaccharide
b. Composed of β-glucose
c. Not digested by amylase
d. All of the above
e. None of the above

39. The grape sugar is
a. Fructose
b. Sucrose
c. Glucose
d. Mannose

40. Lactose is
a. A non-reducing sugar
b. Formed of α-glucose and β-fructose
c. both (a) and (b)
d. None of the above

41. Honey is the natural example for
a. Sucrose
b. Maltose
c. Invert sugar
d. Lactose

42. Reducing property of monosaccharide is tested by
a. Seliwanoff's test
b. Molisch’s test
c. Fehling test
d. Rothera’s test
e. Shape of osazone crystals

43. Inulin is a polymer of
a. Glucose
b. Levulose
c. Galactose
d. Mannose

44. α.glucose is present in structure of
a. Dextrins
b. Dextran
c. Glycogen
d. All of the above

45. Amylase enzyme can hydrolyse
a. Starch
b. Dextrins
c. Glycogen
d. All of the above

46. Glucose and lactose are similar to each other in that both are
a. Reducing
b. Able to give the same osazone
c. Present in milk
d. All of the above


47. Which of the following is a disaccharide?
a. Starch
b. Cellulose
c. Glycogen
d. Ribose
e. Lactose

48. Which carbohydrate will you find in greatest abundance in potatoes?
a. Starch
b. Cellulose
c. Sucrose
d. Glycogen
e. Lactose

49. D-glucuronic acid is an example of
a. Aldonic acid
b. Aldaric acid
c. Uronic acid
d. Saccharic acid
e. None of the above

50. Reduction of monosaccharides yields
a. Sugar alcohols
b. Sugar acids
c. amino sugars
d. Deoxy-sugars
e. None of the above

51. Hydrogen gas in presence of a metal can reduce fructose to
a. Mannitol
b. Ribitol
c. Glycerol
d. Glucose
e. None of the above

52. Cellulose is made up of the molecules of
a. alpha Glucose
b. Beta Glucose
c. Both of above
d. None of the above

53. The epimer of glucose is:
a. Fructose
b. Galactose
c. Ribose
d. Deoxyribose

54. Alpha and Beta forms of D-glucose are referred to as:
a. Epimers
b. Anomers
c. Enediols
d. Tautomers

55. Which of the following does not give a positive test for a reducing sugar?
a. Ribose
b. Galactose
c. Maltose
d. Sucrose

56. Cellulose is a:
a. Branched polymer containing or 1 —> 4 and on 1 —> 6 glycosidic linkages
b. Straight chain polymer consisting of B 1 —> 4 glycosidic units
c. Polymer containing glucose, galactose and glucosamine
d. Mucopolysaccharide

57. In order that a compound possesses optical activity it must be:
a. Colored
b. Symmetrical
c. Inorganic
d. Asymmetric

58. Hydrolysis of sucrose yields:
a. Galactose and glucose
b. Maltose and glucose
c. Fructose only
d. Fructose and glucose


59. Starch and glycogen are both polymers of:
a. Fructose
b. Glucose-1-phosphate
c. Mannose
d. Glucose

60. Which of the following is not a CHO?
a. Amylose
b. Hyaluronic acid
c. Heparin
d. Palmitic acid

61. The predominant carbohydrate of muscle
a. D-fructose
b. D-glucose
c. Lactose
d. Glycogen

62. Lactose is also called:
a. Blood sugar
b. Invert sugar
c. Milk sugar
d. Animal starch

63. An example of pentose is:
a. Galactose
b. Mannose
c. Ribose
d. Fructose

64. An example of Hexose is:
a. Ribose
b. Ribulose
c. Xylulose
d. Mannose

65. A mucopolysaccharide with blood anticoagulant activity is:
a. Chondroitin sulphate B
b. Chondroitin sulphate D
c. Keratan sulphate II
d. Heparin

66. Beta 1-4 glycosidic bond is present in
a. Maltose
b. Lactose
c. Sucrose
d. None of the above

67. Number of stereo-isomers of glucose is :
a. 4
b. 8
c. 16
d. none of the above

68. A homopolysaccharide made up of fructose is :
a. inulin
b. dextrin
c. cellulose
d. glycogen

69. In fructofuranose ,the anomeric carbon is
a. carbon 1
b. carbon 2
c. carbon 3
d. carbon 4

70. A carbohydrate found in the DNA :
a. ribose
b. ribulose
c. deoxyribose
d. all of the above

71. Ribulose is a :
a. ketotetrose
b. aldotetrose
c. ketopentose
d. aldopentose


72. In D-glyecraldehyde, -OH group is present on the right hand side of carbon atom number :
a. 1
b. 2
c. 3
d. 1,2 & 3

73. A disaccharide made up of two glucose units :
a. maltose
b. sucrose
c. dextrin
d. lactose

74. A carbohydrate found only in milk :
a. glucose
b. lactose
c. galactose
d. maltose

75. A carbohydrate ,known commenly as invert sugar :
a. lactose
b. sucrose
c. fractose
d. glucose

76. The homopolysaccharide among the following is :
a. heparin
b. hyaluronic acid
c. dermatan sulphate
d. cellulose

77. The heteropolysaccharide among the following is :
a. inulin
b. starch
c. heparin
d. cellulose


78. In straight chain structure of D-glucose, -OH group is present on the left hand side of carbon atom number :
a. 2
b. 3
c. 4
d. 5

79. The following causes levorotation :
a. D-fructose
b. L-glucose
c. both of them
d. None of them

80. The carbon atom which becomes asymmetric when the straight chain form of monosaccharide changes into ring form is called :
a. anomeric carbon atom
b. epimeric carbon atom
c. isomeric carbon atom
d. none of the above


81. In straight chain structure of D-ribose, -OH group is present on the right hand side of carbon atom number :
a. 2
b. 3
c. 4
d. all of the above

82. In glucopyranose the anomeric carbon atom is number:
a. 2
b. 1
c. 5
d. 6


83. In alpha-D glucopyranose, -OH groups projecting below the plane of the ring, are attached to carbon atoms of numbers:
a. 1,2 & 3
b. 1,2 & 5
c. 1,2 & 4
d. 2,3 & 4

84. Sugar present in DNA is
a. ribose
b. xylulose
c. Arabinose
d. deoxyribose

85. Sugar present in RNA is:
a. Ribose
b. Xylulose
c. Arabinose
d. Deoxyribose

86. Sugar present in seminal fluid is:
a. glucose
b. fructose
c. galactose
d. maltose

87. All the following polysaccharides have glucose as their monomer EXCEPT
a. Starch
b. dextrin
c. Inulin
d. glycogen

88. End product of starch on acid hydrolysis is
a. glucose
b. fructose
c. maltose
d. dextrin

89. End product of enzyme hydrolysis of starch is
a. glucose
b. fructose
c. maltose
d. dextrin

90. Beta 1,4 glycosidic linkages are present in
a. Glycogen
b. starch
c. cellulose
d. inulin

91. All the following are homopolysaccharides EXCEPT
a. Cellulose
b. starch
c. glycogen
d. heparin

92. All the following are heteropolysaccharides EXCEPT
a. Hyaluronic acid
b. chondroitin sulphate
c. Inulin
d. Heparin

93. Which of the following poly saccharine is a naturally occurring anti coagulant?
a. Hylauronic acid
b. chondroitin sulphate
c. heparin
d. keratosulphate


94. One of the following carbohydrates is not digested in the human intestinal tract
a. Starch
b. cellulose
c. lactose
d. sucrose

95. Amylopectin differ from amaylose by
a. alpha 1,4 glycosidic linkage
b. beta 1,4 glycosidic linkage
c. alpha 1,4 glycosidic linkage at branching
d. alpha 1,6 glycosidic linkage at branching

96. One of the following polysaccharides is called animal starch:
a. glucose
b. heparin
c. dextrin
d. glycogen

97. Glucose on oxidation with H2O2 gives:
a. Hyaluronic acid
b. Glucuronic acid
c. Glucaric acid
d. Mucic acid

98. Sorbitol is:
a. A sterol
b. An amino alcohol
c. A sugar alcohol
d. A glycerol derivative

99. The functional group responsible for the reducing property of glucose is present on which carbon atom?
a. 6
b. 5
c. 2
d. 1

Answers
1. D
2. A
3. A
4. B
5. D
6. C
7. B
8. D
9. A
10. D
11. C
12. D
13. B
14. D
15. A
16. E
17. B
18. C
19. C
20. D
21. B
22. B
23. C
24. B
25. C
26. B
27. B
28. C
29. D
30. B
31. A
32. C
33. D
34. B
35. B
36. C
37. C
38. E
39. C
40. D
41. C
42. C
43. B
44. D
45. D
46. A
47. E
48. A
49. C
50. A
51. A
52. B
53. B
54. B
55. D
56. B
57. D
58. D
59. D
60. D
61. D
62. C
63. C
64. D
65. D
66. D
67. C
68. A
69. B
70. C
71. C
72. B
73. A
74. B
75. B
76. D
77. C
78. B
79. C
80. A
81. D
82. B
83. B
84. D
85. A
86. B
87. C
88. A
89. C
90. C
91. D
92. C
93. C
94. B
95. D
96. D
97. B
98. C
99. D



------------------------------------------ Best Wishes: Dr.Ehab Aboueladab, Tel:01007834123 Email:ehab10f@gmail.com,ehababoueladab@yahoo.com ------------------------------------------

Enzymes



1. Group of organic catalysts, protein in nature, present inside the living cells
a- Enzymes
b- Catalysts
c- Hormones
d- None of the above
2. All of the following is true regarding enzymes except …..
a- Heat labile
b- Colloidal
c- Dialyzable
d- High molecular weight
3. Organic substance on which the enzyme acts …….
a- Substrate
b- Co-Enzyme
c- Product
d- None of the above
4. All of the following can be considered as a co Enzyme for transfer of H except
a- Biotin
b- ATP
c- FAD
d- Folic acid
5. One of the following can be considered as a co Enzyme for transfer of groups other than H except
a- Biotin
b- ATP
c- FAD
d- Folic acid


6. One of the following is considered a feature of Enzymes except ……
a- Globular Proteins
b- Undergo Denaturation
c- Simple Proteins
d- Non-Specific
7. Enzyme acts on a special type of bond at specific site and attached to specific groups ……
a- Group Specificity
b- Absolute Specificity
c- Relative Specificity
d- Optical Specificity
8. D-amino acid Oxidase represents ……
a- Group Specificity
b- Absolute Specificity
c- Relative Specificity
d- Optical Specificity
9. Pancreatic Lipase represents …….
a- Group Specificity
b- Absolute Specificity
c- Relative Specificity
d- Optical Specificity

10. Special sequence of amino acids in the protein molecule of the enzyme to which the substrate is attached…….
a- Catalytic Site
b- Active site
c- Allosteric Site
d- None of the above


11. All sequences of amino acids which affect the activity of the enzyme ……
a- Catalytic Site
b- Active site
c- Allosteric Site
d- All of the above
12. Substrate induces a conformational change in the catalytic site …….
a- Lock and key model
b- Flexible model of catalytic site
c- Rigid model of catalytic site
d- None of the above
13. Concentration of the product increases directly by time …….
a- Maximum Velocity
b- End velocity
c- Initial Velocity
d- None of the above
14. Increase in substrate concentration leads to ……..
a- Increase of velocity
b- Increase in enzyme activity
c- Increase of V max
d- All of the above
15. Substrate concentration which produces half maximal velocity (½Vmax.) ……….
a- Full Concentration
b- Null Concentration
c- Michael’s Concentration
d- All of the above



16. Increase in enzyme concentration ……. the rate of reaction
a- Increase
b- Decrease
c- No effect
d- Permissive effect
17. Complete irreversible loss of enzyme activity occurs at ……
a- 37 degree C
b- 45 degree C
c- 0 degree C
d- 60-65 degree C
18. Temperature at which the enzymatic reaction velocity is maximal ……
a- Optimum Temperature
b- 37 degree C
c- 65 degree C
d- A and b together
e- None of the above
19. Optimum PH for Trypsin is ……
a- 6.8
b- 8.4
c- 8
d- 2
20. Optimum PH for Alkaline Phosphatase
a- 6.8
b- 8.4
c- 8
d- 2


21. All of the following inhibits enzymatic activity except
a- Physical Agents
b- Heating
c- Shaking
d- Red and Blue lights
22. Pepsin is activated through ……..
a- Removal of inhibitory peptide
b- Reducing agent
c- Minerals
d- Allosteric activators
23. Glyceraldehyde 3-P dehydrogenase is activated through …..
a- Removal of inhibitory peptide
b- Reducing agent
c- Minerals
d- Allosteric activators
24. Metaloenzymes is activated through …..
a- Removal of inhibitory peptide
b- Reducing agent
c- Minerals
d- Allosteric activators
25. Tyrosinase requires ……
a- ZN ++
b- CU ++
c- CL –
d- MG ++



26. Phosphofructokinase enzyme is activated through …..
a- Removal of inhibitory peptide
b- Reducing agent
c- Minerals
d- Allosteric activators
27. Activation by Phosphorylation excludes one of the following …….
a- Hormone sensitive lipase
b- Glycogen Phosphyrlase
c- Glycogen Synthetase
d- None of the above
28. Competitive inhibition includes all of the following except
a- Chemical structure of the inhibitor closely resembles that of the substrate.
b- Combines Reversibly with the enzyme
c- When both the substrate and the inhibitor are present they compete for the same binding site.
d- V max is decreased
e- Is removed by increases the concentration of inhibitor
29. Reversible noncompetitive Inhibition includes all of the following except
a- I combine with the enzyme away from the catalytic site.
b- The I is not similar to the substrate in structure.
c- The I can combine with the free enzyme or with the enzyme substrate
d- increase the Km
30. Phosphoglyceraldehyde dehydrogenase Resembles …….
a- Reversible Non Competitive Inhibition
b- Irreversible noncompetitive Inhibition
c- Allosteric inhibition
d- Competitive inhibition


31. Increased product concentration …… the enzyme activity
a- Increases
b- Decreases
c- No effect
d- Permissive effect
32. Substances which stimulate gene expression into protein …….
a- Inducer
b- Suppressor
c- Repressors
d- Co-Enzymes
33. Concerning Isoenzymes …….
a- Have quaternary structure and the individual subunits in each isoenzyme are different from the others
b- They act on the different substrate and will give the same product
c- They have different affinity to the substrate.
d- They are present in different tissues.
34. HMMM is present in ……..
a- Heart
b- Kidney
c- Liver
d- Muscles
35. HHMM is present in
a- Kidney
b- Muscles
c- Heart
d- None of the above



36. Non Functional plasma enzymes include all of the following except …..
a- Transaminases ( AST & ALT )
b- Alkaline Phosphatase
c- Lipoprotein lipase
d- None of the above
37. Increased in bone metastasis ………
a- Alkaline phosphatase
b- Creatine kinase
c- LDH
d- None of the above
38. Increased in Prostatic Carcinoma ………
a- Alkaline phosphatase
b- Creatine kinase
c- LDH
d- None of the above
39. Decreased in Galactosemia ………
a- Streptokinase
b- Digestive enzymes
c- Galactosyl transferase
d- α-chymotrypsin
40. Treatment of intraocular hemorrhage is done by
a- Streptokinase
b- Digestive enzymes
c- LDH
d- α-chymotrypsin
41. The oxidation process occurs by ………
a- Addition of oxygen.
b- Removal of hydrogen.
c- Loss of electron
d- All of the above
42. Redoxes that use oxygen as a hydrogen receptor are called ……..
a- Oxidases
b- Hyper peroxidases
c- Dehydrogenases
d- Oxygenases
43. Catalase is specifically abundant in all of the following except ……..
a- Liver
b- Kidney
c- Erythrocytes
d- Milk and leucocytes
44. Enzymes utilizing H2O2 as substrate ……….
a- Oxidases
b- Hyper peroxidases
c- Dehydrogenases
d- Oxygenases

45. LDH depends on ………. In dehydrogenation
a- Nicotinamide
b- FAD
c- C.AMP
d- None of the above
46. Enzymes which catalyze transfer of functional groups (G) other than hydrogen between a pair of substrates …….
a- Transferase
b- Oxygenases
c- Dehydrogenases
d- Hydrolases

47. All of the following are included in Transferase class of enzymes except …….
a- Transaminase
b- Hydrolase
c- Transglycosayl
d- None of the above
48. Split terminal peptide linkage splitting one amino acid at a time is ……..
a- Estrases
b- Endoeptidases
c- Exopeptidases
d- Glycosidases
49. Fumerase is an example of …….
a- Transferase
b- Hydrolase
c- Oxidase
d- Lyases
50. Lipase is an example of …….
a- Transferase
b- Estrases
c- Oxidases
d- Lyases
51. Enzymes link two molecules using energy from ATP ……
a- Lyases
b- Hydrolase
c- Ligase
d- Redox
52. Carboxylase is an example of …….
a- Transferase
b- Estrases
c- Oxidases
d- Ligases
Choose (A) for true and (B) For false of the following
53. Pepsin acts on peptide bonds between amino groups of aromatic amino acid and carboxylic group of another amino acid
54. Enzymes are usually specific in action
55. In Absolute specificity the enzyme acts at different rates on one type of bond in
Compounds chemically related
56. Enzymes may be considered to lower energy barriers for chemical reactions
57. Increase in the substrate concentration will lead to decrease in enzyme activity
58. Increase in enzyme concentration increase the rate of reaction
59. Some enzymes containing SH groups requires Minerals to be activated
60. In Competitive inhibition Vmax of the enzyme is not decreased
61. Inducers are substances which inhibit gene expression
62. Isoenzyme is oligomeric enzyme

Answers
1. A
2. C
3. A
4. C
5. C
6. D
7. A
8. D
9. C
10. A
11. B
12. B
13. C
14. A
15. C
16. A
17. D
18. D
19. C
20. B
21. D
22. A
23. B
24. C
25. B
26. D
27. C
28. D
29. D
30. A
31. B
32. A
33. B
34. D
35. A
36. A
37. A
38. B
39. C
40. D
41. D
42. A
43. D
44. B
45. A
46. A
47. B
48. C
49. D
50. B
51. C
52. D
53. A
54. A
55. B
56. A
57. B
58. A
59. B
60. A
61. B
62. A







------------------------------------------ Best Wishes: Dr.Ehab Aboueladab, Tel:01007834123 Email:ehab10f@gmail.com,ehababoueladab@yahoo.com ------------------------------------------