Carbohydrates Chemistry MCQs PDF

. DR. ZEYAD SAEED |‫د زياد سعيــــد‬ 1 Carbohydrates Chemistry MCQs Collection 1. About carbohydrates: a) derivatives of carbohydrates contain only carbon, hydrogen and oxygen b) monosaccharides are soluble in nonpolar s...

. DR. ZEYAD SAEED |‫د زياد سعيــــد‬ 1 Carbohydrates Chemistry MCQs Collection 1. About carbohydrates: a) derivatives of carbohydrates contain only carbon, hydrogen and oxygen b) monosaccharides are soluble in nonpolar solvents. c) monosaccharides can be hydrolyzed into simpler compounds d) the number of stereoisomers depend on the number of chiral carbon atoms 2. About carbohydrates: a) oligosaccharides consist of long chains of more than 10 monosaccharide units b) all polysaccharides are linear chains c) heteropolysaccharides contain only a single monosaccharide d) a heptose sugar contains 7 carbon atoms 3. Which of the following is an aldotetrose: a) glyceraldehyde b) erythrose c) mannose d) ribose 4. D-xylose is: a) a four carbon aldose b) has four chiral carbons c) involved in DNA synthesis d) a keto sugar e) a five carbon aldose 5. All the following are ketoses except: a) dihydroxyacetone b) ribose c) fructose d) xylulose e) ribulose 6. All of the following are hexose sugars except: a) Mannose b) Arabinose c) Glucose d) Fructose e) Galactose 7. All of the following sugars are hexoses except: a) glucose b) fructose c) mannose d) galactose e) ribose 8. Dextrose is: a) D-glucose b) D-fructose c) dihydroxyacetone d) L-glucose e) L-sucrose 9. About carbohydrates: a) Dihydroxyacetone and glyceraldehyde have the same functional group b) D-ribose and D-arabinose are epimers at carbon number 2 c) D-ribose and D-arabinose are enantiomers d) optical isomers cannot rotate a plane of polarized light 10. How many isomers of sedoheptulose sugar? a) 2 b) 4 c) 12 d) 10 e) 16 11. Galactose contains: a) one asymmetric carbon atom b) two asymmetric carbon atoms c) three asymmetric carbon atoms d) four asymmetric carbon atomsz 12. D-xylulose and D-ribulose are epimers with respect to: a) C1 b) C2 c) C3 d) C4 e) C5. DR. ZEYAD SAEED |‫د زياد سعيــــد‬ 2 13. Mannose and galactose are epimers of glucose at carbon number: a) C2 and C4 respectively b) C2 and C5 respectively c) C3 and C5 respectively d) C1 and C4 respectively e) C3 and C4 respectively 14. Xylose and lyxose are epimers at carbon: a) C5 b) C2 c) C3 d) C4 e) not epimers 15.The following is/are epimers of glucose: a) fructose b) mannose c) ribose d) galactose e) b & d 16. The C2 epimer of glucose is: a) fructose b) galactose c) sedoheptulose d) mannose 17. D-arabinose and D-ribose sugars are epimers with respect to: a) C1 b) C2 c) C3 d) C5 e) C6 18. The D and L isomers of a ribose sugar takes place at: a) C1 b) C2 c) C3 d) C4 e) C5 19. Alpha and beta configuration of D-fructofuranose depends on the position of: a) OH group on C1 with OH on C4 b) OH group on C1 with OH on C6 c) OH group on C2 with OH on C5 d) OH group on C2 with OH on C6 e) OH group on C1 with OH on C5 20. The compound on the right is: a) α-D-glucopyranose b) β-D- glucopyranose c) α-D-galactopyranose d) β-D- galactopyranose e) none of the above 21. Converting α-D-aldose to a β-D-aldose is called: a) reduction b) etherification c) mutarotation d) epimerization e) isomerism 22. The anomeric carbon of fructose is at: a) C1 b) C2 c) C3 d) C4 23. The monosaccharide with no isomerism and asymmetric carbon is: a) glucose b) fructose c) glyceraldehyde d) dihydroxyacetone e) ribose 24. The following is a type of isomerism found only in the ring structure of monosaccharides and not in the open chain form: a) aldose-ketose isomerism b) epimerism c) anomerism d) enantiomerism L & D isomerism 25. How many asymmetric carbons are in ribofuranose? a) one b) two c) three d) four e) five 26. Fructose contains: a) 1 asymmetric carbons b) 2 asymmetric carbons c) 3 asymmetric carbons 4) asymmetric carbons. DR. ZEYAD SAEED |‫د زياد سعيــــد‬ 3 27. How many stereoisomers are possible for a ketohexose: a) 16 b) 12 c) 10 d) 6 e) 8 28. The following are reducing sugars except: a) glucose b) lactose c) sucrose d) fructose e) arabinose 29. Reduction of D-fructose gives: a) only mannitol b) only sorbitol c) mannitol & sorbitol d) none of the above 30. The sugar alcohol form of glucose is: a) galactitol b) mannitol c) sorbitol d) gluconate e) heparin 31. The following is a deoxy sugar: a) glucuronic acid b) iduronic acid c) fucose d) chondrosamine e) sialic acid 32. The following is a five carbon deoxy sugar found in DNA: a) 3` deoxy xylose b) 3` deoxy ribose c) 2` deoxy ribofuranose d) D-ribulose e)D-glucose 33. In amino sugars, the amino group is attached to carbon: a) 1 b) 2 c) 3 d) 4 e) 5 34. All of the following disaccharides consist of pure aldohexoses except: a) Lactulose b) trehalose c) lactose d) maltose e) isomaltose 35. Sucrose (table sugar) is composed of: a) glucose & glucose b) glucose & galactose c) glucose & fructose d) glucose & mannose e) glucose & ribose 36. Maltose and lactose are similar with respect to: a) both are reducing sugars b) both have β-1,4 glycosidic linkage c) both have α-1,4 glycosidic linkage d) both are ketosugars 37. Lactose is a reducing sugar because: a) -OH of carbon number 4 of glucose is not glycosidically linked. b) -OH of carbon number 4 of galactose is not glycosidically linked. c) -OH of anomeric carbon of glucose is not glycosidically linked. d) -OH of anomeric carbon of galactose is not glycosidically linked e) -OH of carbon number 6 of glucose is not glycosidically linked 38. Maltose and lactose are similar in the following except: a) both are reducing sugars b) both are aldosugars c) both have 1,4 glycosidic linkage d) both are made up of galactose 39. Lactose is hydrolyzed into: a) glucose and glucose b) glucose and galactose c) glucose and fructose d) galactose and fructose e) fructose and mannose 40. Inulin is a homopolysaccharide. It consists of: a) Galactose b) Glucose c) Ribose d) Fructose e) Arabinose. DR. ZEYAD SAEED |‫د زياد سعيــــد‬ 4 41. Amylopectin has: a) α 1-4 and α 1-6 linkage b) β 1-2 and α 1-4 linkage c) β 1-4 and α 1-6 linkage d) α 1-4 and β 1-6 linkage 42. What is not true about glycogen: a) has α 1-4 and α 1-6 linkage b) a polymer of galactose c) a homopolysaccharide d) has one reducing end 43. The polysaccharide which prevents constipation is: a) heparan sulfate b) cellulose c) inulin d) heparin 44. All of the following statements are correct about cellulose except: a) it is a heteropolysaccharide b) it is a homopolysaccharide c) it is a useful component in the treatment of constipation d) it contains β 1→4 glycosidic bonds e) it consists of glucose 45. all of the following are correct about inulin except: a) it is a tubers carbohydrates b) it is hydrolysable to fructose c) it is like potato starch d) it is used for testing the glomerular filtration rate e) none of the above is correct 46. All of the following are glucans except: a) cellulose b) inulin c) starch d) dextrins 47. All are true about starch, except: a) it is a heteropolysaccharide b) it is a glucose polymer c) it is composed of amylose and amylopectin d) it is known as a glucan or a glucosan e) it is a homopolysaccharide 48. The following is a branched polysaccharide: a) amylose b) cellulose c) hyaluronic acid d) amylopectin e) heparin 49. About carbohydrates: a) isomaltose contains a α-(1,4) glycosidic bond b) cellobiose is a polysaccharide c) amylose consists of long, branched chains of D-glucose d) Dextrin is produced from partial hydrolysis of starch 50. All of the following may contain α 1,4 – glycosidic bond, except: a) glycogen b) amylopectin c) amylose d) isomaltose e) maltose 51. The bond between sugar units in cellulose is: a) α-(1,4)-N-Glycosidic bond b) β-(1,4)-N-Glycosidic bond c) α-(1,6)-N-Glycosidic bond d) α-(1,4)-O-Glycosidic bond e) β-(1,4)-O-Glycosidic bond. DR. ZEYAD SAEED |‫د زياد سعيــــد‬ 5 52. All of the following are glucosans except: a) amylose b) amylopectin c) glycogen d) cellulose e) inulin 53. The following is a non-branching homopolysaccharide: a) amylopectin b) chitin c) glycogen d) hyaluronic acid d) chondroitin sulphate 54. Amylose are: a) branched homopolysaccharides b) branched heteropolysaccharides c) linear homopolysaccharides d) linear heteropolysaccharides 55. Amylopectin is: a) branched homopolysaccharide b) branched heteropolysaccharide c) linear homopolysaccharide d) linear heteropolysaccharide 56. Amylose is: a) a homopolysaccharide b) non-branching c) helical d) polymer of glucose e) all of the above 57. Cellulose is a polymer of: a) α-D-glucose b) α-D-galactose c) α-D-fructose d) β-D-glucose e) β-D-galactose 58. Cellulose: a) is a polymer of different hexoses b) has β-1,4 –bonds c) has α-1,4-bonds d) is branched e) has β-1,6-bonds 59. It is important to include a sufficient quantity of dietary fibers because: a) it provides more energy for humans than simple carbohydrates b) it adsorbs water producing bulky stool, and adsorbs bile secretion increasing the excretion of cholesterol c) it increases the stool transit time d) it is a cheap diet 60. which of the following is incorrect about inulin? a) it is made up of D-glucose b) it is a homopolysaccharide containing fructose sugar c) it can be used to determine GFR d) can not be digested by humans 61. Polysaccharides containing amino sugars and uronic acid are: a) glycosaminoglycans b) proteoglycans c) glycoproteins d) disaccharides e) chitin 62. Heparin consists of: a) sulfated glucosamine & sulfated glucuronic acid b) N-acetyl galactosamine & glucuronic acid c) N-acetyl galactosamine & iduronic acid d) N-acetyl glucosamine & glucuronic acid e) glucosamine and D-galactose 63. Hyaluronic acid consists of: a) N-acetyl D-galactosamine and L-iduronic acid b) N-acetyl D-glucosamine and D-glucuronic acid c) glucosamine and D-galactose d) N-acetyl D-galactosamine and D-glucuronic acid. DR. ZEYAD SAEED |‫د زياد سعيــــد‬ 6 64. Disaccharide units in keratan sulfates are: a) N-acetylglucosamine and galactose b) N-acetylglucosamine and glucuronic acid c) N-acetylgalactosamine and L-iduronic acid d) N-acetylgalactosamine and glucuronic acid 65. One of the following glycosaminoglycans contains α-1-4 glycosidic bonds: a) hyaluronic acid b) keratan sulfate c) heparan sulfate d) dermatan sulfate 66. Heparin is composed of: a) β-glucuronate and sulfated NaGalA b) β-glucuronate and sulfated NAGA c) sulfated glucosamine + sulfated glucuronic acid d) sulfated glucosamine + sulfated iduronic acid e) sulfated galactosamine + sulfated glucuronic acid 67. Which of the following is an important glycosaminoglycan component of ground substance, synovial fluid and vitreous humor of the eye? a) hyaluronic acid b) uronic acid c) glucuronic acid d) uric acid 68. Proteoglycans are characterized by all of the following except: a) The carbohydrate part is formed of GAGs b) GAGs formed of repeating units formed from uronic acid and hexose c) GAGs contain pentoses and deoxy sugars d) GAGs contain amino sugars 69. About glycoproteins: a) The oligosaccharide chain is attached to asparagine by O-glycosidic bonds b) They play a role in cell surface recognition and antigenicity c) IgG contans more than 60% carbohydrates d) The oligosaccharide chains in glycoproteins are longer than those in glycosaminoglycans 70. All of the following are true about glycophorin except: a) It is an integral membrane protein b) It is present in RBCs c) An oligosaccharide is attached to its outer surface d) a polysaccharide is attached to its inner surface e) it has 130 amino acids 71. About carbohydrates: a) ribose 5 phosphate is important for the structure of nucleic acids b) in reducing sugar, the mutarotation is not possible c) all non-carbohydrate moiety in complex carbohydrates is attached by O-glycosidic bond d) the glycosidic bonds are hydrolyzed by alkaline media 72. N-glycosidic bond connects oligosaccharides with the following amino acid in proteins: a) threonine b) tyrosine c) asparagine d) glycine e) cysteine 73. To digest starch completely, humans use all of the following enzymes except: a) oligosaccharidase b) α-amylase c) isomaltase d) sucrase e) maltase 74. Lactose intolerance: a) developmental lactase deficiency is temporary (improves after some time) b) congenital lactase deficiency is temporary (improves after some time) c) primary lactose intolerance is temporary (improves after some time) d) a and b are correct e) b and c are correct. DR. ZEYAD SAEED |‫د زياد سعيــــد‬ 7 75. Lactose intolerance: a) caused by lactase deficiency b) age dependent c) genetically determined d) more common in Asians e) all of the above 76. Lactase is expressed in humans only in: a) liver b) stomach c) kidney d) pancreas e) small intestine 77. Salivary α-amylase: a) hydrolyzes α(1-4) linkage b) cannot hydrolyze α(1,6) c) cannot hydrolyze disaccharides d) all of the above e) none of the above