General, Organic, and Biochemistry, 2e (Frost) HOMEWORK Chapter 6 Carbohydrates Life s Sweet Molecules 6.1 Multiple-Choice 1) Which of the following is a polysaccharide? Glucose Sucrose C) Starch D) Maltose 2) Which of the following is a disaccharide? Glucose Sucrose C) Starch D) Mannose 3) How many monosaccharides are connected to each other in a disaccharide? 1 2 C) 3 D) 4 4) How many monosaccharides are connected to each other in an oligosaccharide? 1 2 C) 3-9 D) more than 9 5) The general formula for a carbohydrate is: CnH2n+2 Cn(H2O)n C) CnH2n D) Cn(H2O) 6) Which of the following functional groups is just a carbon double bonded to an oxygen atom? Alcohol Thiol C) Carbonyl D) Ester 7) Which of the following functional groups comprises a carbon atom bonded to a hydroxyl group? Alcohol Thiol C) Carbonyl D) Ester 1
8) A carbohydrate with an aldehyde functional group is called: ketose aldose C) disaccharide D) hexose 9) A carbohydrate with a ketone functional group is called: ketose aldose C) disaccharide D) hexose 10) A carbohydrate with 5 carbons is called a: hexose triose C) pentose D) tetrose 11) A carbohydrate with 4 carbons is called a: hexose triose C) pentose D) tetrose 12) A carbohydrate with 6 carbons and an aldehyde functional group is called a(n): ketohexose aldohexose C) ketopentose D) aldopentose 13) A carbohydrate with 6 carbons and a ketone functional group is called a(n): ketohexose aldohexose C) ketopentose D) aldopentose 14) The most abundant monosaccharide in nature is: mannose galactose C) glucose D) fructose 15) Galactose is called a(n): aldopentose ketohexose C) aldohexose D) ketopentose 2
16) Fructose is called a(n): aldopentose ketohexose C) aldohexose D) ketopentose 17) Glyceraldehyde is a carbohydrate that contains? carbon atoms. 3 4 C) 5 D) 6 18) Which of the following is a tertiary alcohol? C) D) 19) Which of the following is a primary alcohol? C) D) 3
20) Which of the following is a secondary alcohol? C) D) 21) Which of the following is an aldehyde functional group? C) D) 22) Which of the following is a ketone functional group? C) 4
D) 23) What types of alcohols are found in carbohydrates? primary secondary C) tertiary D) primary + secondary 24) Which of these carbohydrates shown in the Fischer projection is D-galactose? C) 5
D) 25) Which of these molecules is an aldopentose? 6
C) D) 26) How many stereoisomers are possible for: 1 2 C) 4 7
D) 8 27) How many chiral carbon atoms are there in this molecule? 1 2 C) 3 D) 4 28) The configuration at which carbon atom determines if a monosaccharide is D or L? The lowest numbered chiral carbon The highest numbered chiral carbon C) The chiral carbon closest to the aldehyde or keto group D) The carbon of the primary alcohol group 29) Which of the following compounds is the enantiomer of the following? C) 8
D) 30) Glucose and galactose are of each other. anomers enantiomers C) epimers D) cis-trans isomers 31) Which of these molecules is the enantiomer of D-altrose? 9
C) D) 32) Which one of these molecules is an epimer of D-allose? 10
C) 11
D) 33) Which of the following is a pyranose ring? C) Both of these are pyranose rings. D) Neither of these is a pyranose ring. 12
34) Which of the following is a furanose ring? C) Both of these are furanose rings. D) Neither of these is a furanose ring. 13
35) α-d-glucose and β-d-glucose are: enantiomers anomers C) disaccharides D) a racemic mixture 36) When an organic molecule loses hydrogens it is said to be: reduced oxidized C) both oxidized and reduced D) neither oxidized or reduced 37) When an organic molecule gains hydrogens it is said to be: reduced oxidized C) both oxidized and reduced D) neither oxidized or reduced 38) When a substance is oxidized it is called a(n): oxidizing agent reducing agent C) both D) neither 39) When a substance is reduced it is called a(n): oxidizing agent reducing agent C) both D) neither 40) In the Benedict's test: an aldehyde is oxidized a silver mirror is produced C) the copper (II) ion is oxidized D) all of these 41) In the Benedict's test: an aldehyde is oxidized a brick red precipitate is formed C) the copper (II) ion is reduced D) all of the above are true 42) The substance that precipitates in a positive Benedict test is: Ag CuO C) Cu2O D) none of these 14
43) Lactose is made from D-glucose and: mannose glucose C) galactose D) ribose 44) Which of the following is a non-reducing sugar? Lactose Glucose C) Mannose D) Sucrose 45) This disaccharide is also known as malt sugar since it is formed from the breakdown of starch and is a key ingredient in beer: sucrose lactose C) maltose D) cellobiose 46) What type of glycosidic bond is shown here? α(1 4) α(1 6) C) β(1 4) D) β(1 6) 47) What type of glycosidic bond is shown here? 15
α(1 4) α(1 6) C) β(1 4) D) β(1 6) 48) The glycosidic bond that connects the two monosaccharides in lactose is: α(1 4) β(1 4) C) α(1 6) D) α,β(1 2) 49) The glycosidic bond that connects the two monosaccharides in sucrose is: α(1 4) β(1 4) C) α(1 6) D) α,β(1 2) 50) Which of these polysaccharides is not made exclusively from α-glucose units amylose amylopection C) glycogen D) cellulose 51) Which of the following is the storage form of glucose in the liver and muscle tissue? Amylose Amylopectin C) Glycogen D) Cellulose 52) Which one of these polysaccharides is not used in energy storage? cellulose glycogen C) amylose D) amylopectin 16
53) Which blood type contains the carbohydrate N-acetylgalactosamine? A B C) O D) All types of blood 54) Which of the following blood types is considered to be the universal blood donor? Type B Type A C) Type AB D) Type O Practice questions (TRUE/FALSE): 1) This molecule represents an aldehyde: 4) This molecule represents a ketone: 17
5) This molecule represents a ketopentose: 18
6) This molecule represents an aldohexose: 7) This molecule represents the L enantiomer of galactose: 19
11) Starch is made from glucose units in α(1 4) glycosidic bonds. 12) Glycogen is the storage polysaccharide in animals. 6.3 Short Answer 1) Identify which structure contains a primary, secondary or tertiary alcohol in the following structures. C) 3) Given the following structure: How many chiral carbons are contained in this compound? Identify each chiral carbon. How many stereoisomers are possible for this compound? 20