General, Organic & Biological Chemistry, 5e (Timberlake) Chapter 15 Carbohydrates 15.1 Multiple-Choice Questions 1) A carbohydrate that gives two molecules when it is completely hydrolyzed is known as a A) monosaccharide B) disaccharide C) polysaccharide D) starch E) trisaccharide Answer: B Objective: 15.1 Global Outcomes: GO2 2) Which group of carbohydrates cannot be hydrolyzed to give smaller molecules? A) monosaccharides B) disaccharides C) trisaccharides D) oligosaccharides E) polysaccharides Answer: A Objective: 15.1 Global Outcomes: GO2 3) A monosaccharide that consists of carbon atoms, one of which is in a ketone group, is classified as a(n) A) aldotetrose B) aldopentose C) aldohexose D) ketotetrose E) ketopentose Answer: E Objective: 15.1 Global Outcomes: GO2 4) A monosaccharide that contains carbon atoms, one of which is in an aldehyde group, is classified as a(n) A) aldopentose B) aldohexose C) ketopentose D) aldotetrose E) ketotetrose Answer: D Objective: 15.1 Global Outcomes: GO2 Copyright © 2016 Pearson Education, Inc 5) Which of the following is an example of an aldopentose? A) B) C) D) E) Answer: C Objective: 15.1 Global Outcomes: GO2 Copyright © 2016 Pearson Education, Inc 6) Ribulose has the following structural formula To what carbohydrate class does ribulose belong? CH2OH ∣ C=O ∣ H - C - OH ∣ H - C - OH ∣ CH2OH A) aldotetrose B) aldopentose C) ketotetrose D) ketopentose E) ketohexose Answer: D Objective: 15.1 Global Outcomes: GO2 7) During photosynthesis, carbon dioxide and water are converted to glucose and oxygen by A) large animals B) insects C) mushrooms D) green plants E) earthworms Answer: D Objective: 15.1 Global Outcomes: GO7 8) The breakdown of carbohydrates to carbon dioxide and water in the body is called A) reduction B) respiration C) photosynthesis D) anabolism E) mutarotation Answer: B Objective: 15.1 Global Outcomes: GO7 Copyright © 2016 Pearson Education, Inc 9) Which of the following is an example of a ketopentose? A) B) C) D) E) Answer: D Objective: 15.1 Global Outcomes: GO2 Copyright © 2016 Pearson Education, Inc 10) Which of the following is an example of an aldohexose? A) B) C) D) E) Answer: E Objective: 15.1 Global Outcomes: GO2 11) The breakdown of glucose to chemical energy for the cells to work is an example of A) oxidation Copyright © 2016 Pearson Education, Inc B) respiration C) reduction D) anabolism E) mutarotation Answer: A Objective: 15.1 Global Outcomes: GO2 12) Photosynthesis uses as an energy source A) glucose B) carbon dioxide C) chlorophyll D) oxygen E) sunlight Answer: E Objective: 15.1 Global Outcomes: GO2 13) Fructose does not undergo hydrolysis because it is a A) aldose B) hexose C) reducing sugar D) monosaccharide E) disaccharide Answer: D Objective: 15.1 Global Outcomes: GO2 14) Galactosemia is the name of a metabolic disorder In this disorder, an enzyme is missing that is needed to A) make galactose from lactose B) make lactose from galactose C) convert galactose to glycogen D) convert galactose to glucose E) convert α-galactose to β-galactose Answer: D Objective: 15.2 Global Outcomes: GO7 Copyright © 2016 Pearson Education, Inc 15) Which Fischer projection is the mirror image of the structure given below? Br ∣ HO — Cl ∣ CH3 A) Br ∣ HO — CH3 ∣ Cl B) Br ∣ Cl — OH ∣ CH3 C) OH ∣ CH3 — Cl ∣ Br D) CH3 ∣ Br — Cl ∣ OH E) Br ∣ CH3 — Cl ∣ OH Answer: B Objective: 15.2 Global Outcomes: GO2 Copyright © 2016 Pearson Education, Inc 16) In the L- isomer of a Fischer projection of a monosaccharide, the -OH group furthest from the carbonyl is written A) on the left of the top chiral carbon B) on the right of the top chiral carbon C) on the left of the middle chiral carbon D) on the left of the bottom chiral carbon E) on the right of the bottom chiral carbon Answer: D Objective: 15.2 Global Outcomes: GO2 17) One difference between D-glucose and L-glucose is A) the open-chain form of L-glucose does not exist B) it is not possible to make L-glucose C) L-glucose has a 5-membered ring, and D-glucose has a 6-membered ring D) only D-glucose is found in disaccharides and polysaccharides E) L-glucose cannot form a closed structure Answer: D Objective: 15.2 Global Outcomes: GO2 18) Hyperglycemia is a condition in which A) the glucose level in the blood is about 100 mg/dL B) the amount of glucose in the urine is lower than normal C) the glucose level in the blood is higher than normal D) the glucose level in the pancreas is lower than normal E) the glucose level in the liver is lower than normal Answer: C Objective: 15.2 Global Outcomes: GO7 19) Hypoglycemia is a condition in which A) the glucose level in the blood is about 100 mg/dL B) the amount of glucose in the urine is higher than normal C) the glucose level in the blood is higher than normal D) the glucose level in the pancreas is higher than normal E) the glucose level in the blood is lower than normal Answer: E Objective: 15.2 Global Outcomes: GO7 Copyright © 2016 Pearson Education, Inc 20) The sugar also known as dextrose and blood sugar is A) glucose B) galactose C) fructose D) lactose E) sucrose Answer: A Objective: 15.2 Global Outcomes: GO7 21) Galactose has the structure shown below It can be classified as a(n) A) ribose B) ketose C) disaccharide D) monosaccharide E) ketone Answer: D Objective: 15.3 Global Outcomes: GO2 22) Galactose has the structure shown below Which anomer is shown? A) the α anomer B) the β anomer C) the D anomer D) the L anomer E) none of the above Answer: B Objective: 15.3 Global Outcomes: GO2 Copyright © 2016 Pearson Education, Inc 23) Mannose has the structure shown below Which anomer is shown? A) the α anomer B) the β anomer C) the D anomer D) the L anomer E) none of the above Answer: A Objective: 15.3 Global Outcomes: GO2 24) The conversion between α and β anomers is called A) oxidation B) reduction C) glycoside D) mutarotation E) hydrolysis Answer: D Objective: 15.3 Global Outcomes: GO2 25) The reduction of monosaccharides produces A) sugar alcohols B) disaccharides C) trisaccharides D) sugar acids E) polysaccharides Answer: A Objective: 15.4 Global Outcomes: GO2 26) The oxidation of monosaccharides produces A) sugar alcohols B) disaccharides C) trisaccharides D) sugar acids E) polysaccharides Answer: D Objective: 15.4 Global Outcomes: GO2 10 Copyright © 2016 Pearson Education, Inc 27) A glycosidic bond between two monosaccharides can also be classified as a(n) A) double bond B) ester bond C) ether bond D) achiral bond E) alcohol bond Answer: C Objective: 15.5 Global Outcomes: GO2 28) In a disaccharide, two monosaccharides are joined by what kind of bond? A) double B) anomeric C) alcohol D) glycosidic E) rotational Answer: D Objective: 15.5 Global Outcomes: GO2 29) Which of the following contains a β-1,4-glycosidic bond? A) galactose B) lactose C) maltose D) sucrose E) amylose Answer: B Objective: 15.5 Global Outcomes: GO2 30) Which sugar is NOT a reducing sugar? A) glucose B) fructose C) galactose D) maltose E) sucrose Answer: E Objective: 15.5 Global Outcomes: GO2 31) Aspartame® and Saccharin® are two examples of A) disaccharides B) polysaccharides C) chlorosaccharides D) alcohol sweeteners E) noncarbohydrate sweeteners Answer: E Objective: 15.5 Global Outcomes: GO7 Refer to the disaccharides below to answer the question(s) that follow 11 Copyright © 2016 Pearson Education, Inc 32) In the figure above, the monosaccharide unit at the top is a(n) A) aldopentose B) ketopentose C) aldohexose D) aldoheptose E) ketohexose Answer: E Objective: 15.5 Global Outcomes: GO2 33) In the figure above, the monosaccharide unit on the bottom is a(n) A) aldopentose B) ketopentose C) aldohexose D) aldoheptose E) ketohexose Answer: C Objective: 15.5 Global Outcomes: GO2 34) Hydrolysis of the disaccharide above gives the monosaccharides A) fructose and ribose B) fructose and galactose C) ribose and glucose D) ribose and galactose E) fructose and lactose Answer: B Objective: 15.5 Global Outcomes: GO2 12 Copyright © 2016 Pearson Education, Inc 35) The disaccharide above contains a(n) -glycosidic linkage A) α-1,4 B) β-1,4 C) α-2,4 D) β-2,4 E) α-2,6 Answer: E Objective: 15.5 Global Outcomes: GO2 36) Maltose is a A) monosaccharide B) disaccharide C) trisaccharide D) polysaccharide E) phosphosaccharide Answer: B Objective: 15.5 Global Outcomes: GO2 37) Galactose is a product of enzymatic hydrolysis of A) lactose B) glucose C) maltose D) erythrose E) sucrose Answer: A Objective: 15.5 Global Outcomes: GO2 38) Maltose can be classified as a(n) A) disaccharide B) polysaccharide C) ketose D) pentose E) oligosaccharide Answer: A Objective: 15.5 Global Outcomes: GO2 39) Which of the following contains α-1,6-branches? A) amylose B) glycogen C) cellulose D) sucrose E) maltose Answer: B Objective: 15.6 Global Outcomes: GO2 40) Cellulose is not digestible by humans because it contains glucose units linked by -glycosidic bonds A) α-1,2 B) α-1,4 C) α-1,6 D) β-1,2 E) β-1,4 13 Copyright © 2016 Pearson Education, Inc Answer: E Objective: 15.6 Global Outcomes: GO2 41) Amylose is a polysaccharide which has A) only β-1,4-bonds between glucose units B) only α-1,4-links bonds glucose units C) both α-1,4-and β-1,4-bonds between glucose units D) hemiacetal links joining glucose units E) carbon-carbon bonds joining glucose units Answer: B Objective: 15.6 Global Outcomes: GO2 42) Humans cannot digest cellulose because they A) lack the necessary enzymes to digest β-glycosides B) are allergic to β-glycosides C) are poisoned by β-glycosides D) have intestinal flora which use up β-glycosides E) cannot digest chlorophyll Answer: A Objective: 15.6 Global Outcomes: GO7 43) Under acid hydrolysis conditions, starch is converted to A) glucose B) xylose C) maltose D) galactose E) fructose Answer: A Objective: 15.6 Global Outcomes: GO2 14 Copyright © 2016 Pearson Education, Inc 44) Amylopectin is a polysaccharide which has A) only β-1,4-bonds between glucose units B) only α-1,4-links bonds glucose units C) both α-1,4-and β-1,4-bonds between glucose units D) both α-1,4-and α-1,6-bonds between glucose units E) carbon-carbon bonds joining glucose units Answer: D Objective: 15.6 Global Outcomes: GO2 45) Glycogen is a polysaccharide which has A) only β-1,4-bonds between glucose units B) only α-1,4-links bonds glucose units C) both α-1,4-and β-1,4-bonds between glucose units D) both α-1,4-and α-1,6-bonds between glucose units E) carbon-carbon bonds joining glucose units Answer: D Objective: 15.6 Global Outcomes: GO2 15.2 Short Answer Questions State whether each of these structures is the α- or β-form 1) Answer: α (alpha) Objective: 15.3 Global Outcomes: GO2 2) Answer: β (beta) Objective: 15.3 Global Outcomes: GO2 15 Copyright © 2016 Pearson Education, Inc 3) Answer: α (alpha) Objective: 15.3 Global Outcomes: GO2 4) Answer: α (alpha) Objective: 15.3 Global Outcomes: GO2 5) Answer: β (beta) Objective: 15.3 Global Outcomes: GO2 16 Copyright © 2016 Pearson Education, Inc Identify each Fischer projection as the D- or L-isomer 6) Answer: D Objective: 15.2 Global Outcomes: GO2 7) Answer: L Objective: 15.2 Global Outcomes: GO2 8) Answer: L Objective: 15.2 Global Outcomes: GO2 17 Copyright © 2016 Pearson Education, Inc 9) Answer: L Objective: 15.2 Global Outcomes: GO2 10) Answer: D Objective: 15.2 Global Outcomes: GO2 15.3 True/False Questions 1) A monosaccharide can be hydrolyzed to smaller units Answer: FALSE Objective: 15.1 Global Outcomes: GO2 2) Fructose is also known as dextrose Answer: FALSE Objective: 15.2 Global Outcomes: GO2 3) Fructose is a ketohexose Answer: TRUE Objective: 15.2 Global Outcomes: GO2 4) In the D- isomer, the -OH farthest from the carbonyl is to the left Answer: FALSE Objective: 15.2 Global Outcomes: GO2 18 Copyright © 2016 Pearson Education, Inc 5) In the α anomer of glucose, the OH on carbon is above the plane of the ring Answer: FALSE Objective: 15.3 Global Outcomes: GO2 6) This anomer is the α anomer Answer: FALSE Objective: 15.3 Global Outcomes: GO2 7) A reducing sugar gives a precipitate of silver metal with Benedict's reagent Answer: FALSE Objective: 15.4 Global Outcomes: GO2 8) Cellulose will give a positive Benedict's test Answer: FALSE Objective: 15.4 Global Outcomes: GO2 9) The product of oxidation of an aldose is a carboxylic acid Answer: TRUE Objective: 15.4 Global Outcomes: GO2 10) The product of reduction of mannose is mannic acid Answer: FALSE Objective: 15.4 Global Outcomes: GO2 11) Sucrose is a reducing sugar Answer: FALSE Objective: 15.4 Global Outcomes: GO2 12) Maltose is a reducing sugar Answer: TRUE Objective: 15.4 Global Outcomes: GO2 13) The product of reduction of xylose is xylitol Answer: TRUE Objective: 15.4 Global Outcomes: GO2 14) Sucrose is made up of glucose units only Answer: FALSE Objective: 15.5 Global Outcomes: GO2 15) Galactose is a disaccharide Answer: FALSE 19 Copyright © 2016 Pearson Education, Inc Objective: 15.5 Global Outcomes: GO2 16) Sucrose is a disaccharide Answer: TRUE Objective: 15.5 Global Outcomes: GO2 17) The iodine test is used to detect the presence of a reducing sugar Answer: FALSE Objective: 15.6 Global Outcomes: GO2 18) Glucose is stored in animals as glycogen Answer: TRUE Objective: 15.6 Global Outcomes: GO2 19) Amylopectin is a straight-chain polysaccharide Answer: FALSE Objective: 15.6 Global Outcomes: GO2 20) Cellulose is a polysaccharide with only β-1,4-bonds between glucose units Answer: TRUE Objective: 15.6 Global Outcomes: GO2 20 Copyright © 2016 Pearson Education, Inc 15.4 Matching Questions Select the correct carbohydrate for each description A) amylose B) fructose C) lactose D) cellulose E) galactose F) glycogen G) maltose H) sucrose 1) a carbohydrate that cannot be digested by humans Objective: 15.2, 15.5, 15.6 Global Outcomes: GO2 2) a disaccharide that occurs as a breakdown product of starch Objective: 15.2, 15.5, 15.6 Global Outcomes: GO2 3) a carbohydrate that stores energy in the human body Objective: 15.2, 15.5, 15.6 Global Outcomes: GO2 4) a carbohydrate that is used to build cell walls in plants Objective: 15.2, 15.5, 15.6 Global Outcomes: GO2 5) a monosaccharide that combines with glucose to form lactose Objective: 15.2, 15.5, 15.6 Global Outcomes: GO2 6) a disaccharide found in milk and milk products Objective: 15.2, 15.5, 15.6 Global Outcomes: GO2 7) a disaccharide consisting of glucose and fructose Objective: 15.2, 15.5, 15.6 Global Outcomes: GO2 8) a disaccharide consisting of two glucose molecules Objective: 15.2, 15.5, 15.6 Global Outcomes: GO2 9) a monosaccharide found in fruit juices and honey, the sweetest carbohydrate Objective: 15.2, 15.5, 15.6 Global Outcomes: GO2 21 Copyright © 2016 Pearson Education, Inc 10) an unbranched carbohydrate that stores glucose in plants Objective: 15.2, 15.5, 15.6 Global Outcomes: GO2 Answers: 1) D 2) G 3) F 4) D 5) E 6) C 7) H 8) G 9) B 10) A Indicate the monosaccharide(s) produced upon hydrolysis of each carbohydrate A) glucose + fructose B) glucose C) glucose + galactose 11) amylopectin Objective: 15.5, 15.6 Global Outcomes: GO2 12) lactose Objective: 15.5, 15.6 Global Outcomes: GO2 13) glycogen Objective: 15.5, 15.6 Global Outcomes: GO2 14) maltose Objective: 15.5, 15.6 Global Outcomes: GO2 15) sucrose Objective: 15.5, 15.6 Global Outcomes: GO2 Answers: 11) B 12) C 13) B 14) B 15) A 22 Copyright © 2016 Pearson Education, Inc ... Objective: 15. 2, 15. 5, 15. 6 Global Outcomes: GO2 6) a disaccharide found in milk and milk products Objective: 15. 2, 15. 5, 15. 6 Global Outcomes: GO2 7) a disaccharide consisting of glucose and fructose... Objective: 15. 5, 15. 6 Global Outcomes: GO2 12) lactose Objective: 15. 5, 15. 6 Global Outcomes: GO2 13) glycogen Objective: 15. 5, 15. 6 Global Outcomes: GO2 14) maltose Objective: 15. 5, 15. 6 Global... Objective: 15. 2, 15. 5, 15. 6 Global Outcomes: GO2 8) a disaccharide consisting of two glucose molecules Objective: 15. 2, 15. 5, 15. 6 Global Outcomes: GO2 9) a monosaccharide found in fruit juices and