Question 1

What type of compound is produced in the reaction between an alcohol and an aldehyde?

Accepted Answer

A) diol 
B) carboxylic acid 
C) acetal 
D) hemiacetal 
E) ester 
A) diol 
B) carboxylic acid 
C) acetal 
D) hemiacetal 
E) ester

Question 2

Which of the following statements concerning stereochemistry is INCORRECT?

Accepted Answer

A) Stereoisomers are molecules with the same molecular formula, same bonding pattern, but different spatial arrangement of atoms. 
B) A chiral carbon is a carbon atom that has four different groups bonded to it. 
C) A molecule that contains a chiral carbon is a chiral molecule, and exists as a pair of enantiomers. 
D) Enantiomers are superimposable mirror image stereoisomers. 
E) A racemic mixture of enantiomers is optically inactive. 
A) Stereoisomers are molecules with the same molecular formula, same bonding pattern, but different spatial arrangement of atoms. 
B) A chiral carbon is a carbon atom that has four different groups bonded to it. 
C) A molecule that contains a chiral carbon is a chiral molecule, and exists as a pair of enantiomers. 
D) Enantiomers are superimposable mirror image stereoisomers. 
E) A racemic mixture of enantiomers is optically inactive.

Question 3

If D-glucose is levorotatory, then L-glucose must be levorotatory as well.

Accepted Answer

A) True 
 B)False

Question 4

What type of product forms in the intramolecular reaction between the aldehyde portion of the glucose molecule below and its C-5 hydroxyl group?

Accepted Answer

A) disaccharide 
B) ester 
C) carboxylic acid 
D) stereoisomer 
E) hemiacetal 
A) disaccharide 
B) ester 
C) carboxylic acid 
D) stereoisomer 
E) hemiacetal

Question 5

What complex carbohydrate provides a source of dietary fiber?

Accepted Answer

A) starch 
B) cellulose 
C) lactose 
D) sucrose 
E) glucose 
A) starch 
B) cellulose 
C) lactose 
D) sucrose 
E) glucose

Question 6

Which of the following is NOT a carbohydrate?

Accepted Answer

A) sucrose 
B) simple sugar 
C) fatty acid 
D) cellulose 
E) starch 
A) sucrose 
B) simple sugar 
C) fatty acid 
D) cellulose 
E) starch

Question 7

Which enantiomer of glyceraldehyde is represented in the following structure?

Accepted Answer

A) trans 
B) α 
C) β 
D) D 
E) L 
A) trans 
B) α 
C) β 
D) D 
E) L

Question 8

What two monosaccharides combine to form sucrose?

Accepted Answer

A) glucose and galactose 
B) galactose and fructose 
C) ribose and galactose 
D) glucose and fructose 
E) ribose and fructose 
A) glucose and galactose 
B) galactose and fructose 
C) ribose and galactose 
D) glucose and fructose 
E) ribose and fructose

Question 9

Which carbohydrate is present in RNA?

Accepted Answer

A) ribulose 
B) glucose 
C) mannose 
D) ribose 
E) fructose 
A) ribulose 
B) glucose 
C) mannose 
D) ribose 
E) fructose

Question 10

Cellulose molecules are all unbranched, while starch contains only branched molecules.

Accepted Answer

A) True 
 B)False

Question 11

Starch is composed of which two polysaccharides?

Accepted Answer

A) chitin and chondroitin 
B) glycogen and cellulose 
C) amylose and amylopectin 
D) glucosamine and glycogen 
E) cellulose and galactosamine 
A) chitin and chondroitin 
B) glycogen and cellulose 
C) amylose and amylopectin 
D) glucosamine and glycogen 
E) cellulose and galactosamine

Question 12

What test can be used to distinguish between a reducing sugar and a nonreducing sugar?

Accepted Answer

A) iodine test 
B) Tollens' test 
C) chromic acid test 
D) Benedict's test 
E) hydrolysis test 
A) iodine test 
B) Tollens' test 
C) chromic acid test 
D) Benedict's test 
E) hydrolysis test

Question 13

What polysaccharide found in animals has a structure very similar to amylopectin?

Accepted Answer

A) glucose 
B) glycogen 
C) starch 
D) amylose 
E) cellulose 
A) glucose 
B) glycogen 
C) starch 
D) amylose 
E) cellulose

Question 14

Melibiose is a carbohydrate found in some plant juices.Which of the following statements concerning melibiose is INCORRECT?

Accepted Answer

A) It is a disaccharide. 
B) It is composed of two different monosaccharide units. 
C) It contains both an acetal and a hemiacetal. 
D) It contains an α(1→5) glycosidic linkage. 
E) It is a reducing sugar. 
A) It is a disaccharide. 
B) It is composed of two different monosaccharide units. 
C) It contains both an acetal and a hemiacetal. 
D) It contains an α(1→5) glycosidic linkage. 
E) It is a reducing sugar.

Question 15

All monosaccharides give a positive result with Benedict's reagent.

Accepted Answer

A) True 
 B)False

Question 16

What term describes a carbon atom that has four different groups bonded to it?

Accepted Answer

A) chiral 
B) unbalanced 
C) trigonal pyramidal 
D) meso 
E) unsaturated 
A) chiral 
B) unbalanced 
C) trigonal pyramidal 
D) meso 
E) unsaturated

Question 17

How do the structures of amylose and cellulose differ?

Accepted Answer

A) Amylose is a linear polysaccharide and cellulose is a branched polysaccharide. 
B) Amylose is a homopolysaccharide and cellulose is a heteropolysaccharide. 
C) Amylose is a polysaccharide of glucose units, and cellulose is a polysaccharide of galactose units. 
D) Amylose is a polysaccharide made up of D-glucose units, and cellulose is a polysaccharide made up of L-glucose units. 
E) Amylose contains α(1→4) glycosidic bonds joining D-glucose units, and cellulose contains β(1→4) glycosidic bonds joining D-glucose units. 
A) Amylose is a linear polysaccharide and cellulose is a branched polysaccharide. 
B) Amylose is a homopolysaccharide and cellulose is a heteropolysaccharide. 
C) Amylose is a polysaccharide of glucose units, and cellulose is a polysaccharide of galactose units. 
D) Amylose is a polysaccharide made up of D-glucose units, and cellulose is a polysaccharide made up of L-glucose units. 
E) Amylose contains α(1→4) glycosidic bonds joining D-glucose units, and cellulose contains β(1→4) glycosidic bonds joining D-glucose units.

Question 18

The Fischer projections of two monosaccharides are shown below.What is the relationship between the two monosaccharides?

Accepted Answer

A) enantiomers 
B) diastereomers 
C) structural isomers 
D) meso isomers 
E) cis-trans isomers 
A) enantiomers 
B) diastereomers 
C) structural isomers 
D) meso isomers 
E) cis-trans isomers

Question 19

The monosaccharide derivative shown below bonds to hydrophobic molecules in the liver.What effect does this have on the molecule to which it binds?

Accepted Answer

A) It increases the hydrophobicity of the molecule, making it more soluble in fatty tissues. 
B) It increases the polarity of the molecule, making it more soluble in bodily fluids, and more readily removed. 
C) It eliminates the ability of the molecule to act as a nutritional source of energy. 
D) It decreases the polarity of the hydrophobic molecule, allowing it to be retained in the body longer. 
E) It increases the nutritional value of the molecule by allowing it to be retained by the body longer. 
A) It increases the hydrophobicity of the molecule, making it more soluble in fatty tissues. 
B) It increases the polarity of the molecule, making it more soluble in bodily fluids, and more readily removed. 
C) It eliminates the ability of the molecule to act as a nutritional source of energy. 
D) It decreases the polarity of the hydrophobic molecule, allowing it to be retained in the body longer. 
E) It increases the nutritional value of the molecule by allowing it to be retained by the body longer.

Question 20

Propranol is a chiral compound that exists as a pair of enantiomers.One enantiomer is used to treat irregular heartbeats, and the other is used as a contraceptive.Which labeled carbon atom(s) is/are chiral?

Accepted Answer

A) C-1 
B) C-2 
C) C-3 
D) C-4 
E) C-1 and C-3 
A) C-1 
B) C-2 
C) C-3 
D) C-4 
E) C-1 and C-3

Exam 16: Carbohydrates

What type of compound is produced in the reaction between an alcohol and an aldehyde?

Which of the following statements concerning stereochemistry is INCORRECT?

If D-glucose is levorotatory, then L-glucose must be levorotatory as well.

What type of product forms in the intramolecular reaction between the aldehyde portion of the glucose molecule below and its C-5 hydroxyl group?

What complex carbohydrate provides a source of dietary fiber?

Which of the following is NOT a carbohydrate?

Which enantiomer of glyceraldehyde is represented in the following structure?

What two monosaccharides combine to form sucrose?

Which carbohydrate is present in RNA?

Cellulose molecules are all unbranched, while starch contains only branched molecules.

Starch is composed of which two polysaccharides?

What test can be used to distinguish between a reducing sugar and a nonreducing sugar?

What polysaccharide found in animals has a structure very similar to amylopectin?

Melibiose is a carbohydrate found in some plant juices.Which of the following statements concerning melibiose is INCORRECT?

All monosaccharides give a positive result with Benedict's reagent.

What term describes a carbon atom that has four different groups bonded to it?

How do the structures of amylose and cellulose differ?

The Fischer projections of two monosaccharides are shown below.What is the relationship between the two monosaccharides?

The monosaccharide derivative shown below bonds to hydrophobic molecules in the liver.What effect does this have on the molecule to which it binds?

Propranol is a chiral compound that exists as a pair of enantiomers.One enantiomer is used to treat irregular heartbeats, and the other is used as a contraceptive.Which labeled carbon atom(s) is/are chiral?

Chemistry:methods and Measurement

The Structure of the Atom and the Periodic Table

Structure and Properties of Ionic and Covalent Compounds

Calculations, Chemical Changes, and the Chemical Equation

States of Matter- Gases, Liquids, and Solids

Solutions

Energy, Rate and Equilibrium

Acids and Bases

The Nucleus, Radioactivity, and Nuclear Medicine

An Introduction to Organic Chemistry- the Saturated Hydrocarbons

The Unsaturated Hydrocarbons- Alkenes, Alkynes, and Aromatics

Alcohols, Phenols, Thiols, and Ethers

Aldehydes and Ketones

Carboxylic Acids and Carboxylic Acid Derivatives

Amines and Amides

Lipids and Their Functions in Biochemical Systems

Protein Structure and Function

Enzymes

Introduction to Molecular Genetics

Carbohydrate Metabolism

Aerobic Respiration and Energy Production

Fatty Acid Metabolism

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