Question 1

Use the following to answer the questions below:
In each of the following multiple-choice questions, characterize EACH of the three given statements as being TRUE or FALSE and then indicate the collective true-false status of the statements using the choices:
-Statements: 
(1) Enantiomers with more than three carbon atoms must have the same handedness.
(2) The molecules glyceraldehyde and dihydroxyketone each contain one chiral center.
(3) Glucose contain one more -OH group than does galactose.

Accepted Answer

1) False. Enantiomers are mirror images of each other and must have opposite handedness, regardless of the number of carbon atoms. 2) False. Glyceraldehyde has one chiral center, but dihydroxyacetone has no chiral centers because it is a symmetrical molecule. 3) False. Glucose and galactose both contain the same number of -OH groups; they differ in the orientation of the -OH group on one of their carbons.

Question 2

Use the following to answer the questions below:
For each of the stereochemical descriptions, select from the response list an appropriate set of structural formulas. Responses may be used more than once or need not be used at all. 
-Optical isomers

Accepted Answer

The answer of Use the following to answer the questions...

Question 3

Use the following to answer the questions below:
For each of the disaccharides or polysaccharides, select from the response list the correct hydrolysis products. Responses may be used more than once or need not be used at all.

-Sucrose

Accepted Answer

Sucrose is a disaccharide composed of glucose and fructose. When it is hydrolyzed, it breaks down into these two monosaccharides. Hence, choice C is the correct hydrolysis products for sucrose.

Question 4

Use the following to answer the questions below:
For each of the stereochemical descriptions, select from the response list an appropriate set of structural formulas. Responses may be used more than once or need not be used at all. 
-Mirror images

Accepted Answer

The answer of Use the following to answer the questions...

Question 5

Use the following to answer the questions below:
For each of the compound characterizations, select from the response list an appropriate structural formula. Responses may be used more than once or need not be used at all. 
-An achiral compound

Accepted Answer

The answer of Use the following to answer the questions...

Question 6

Use the following to answer the questions below:
In each of the following multiple-choice questions, characterize EACH of the three given statements as being TRUE or FALSE and then indicate the collective true-false status of the statements using the choices:
-Statements: (1) The term sugar is a general designation for both monosaccharides and disaccharides.
(2) The "highest-numbered" chiral center in a monosaccharide is used to determine D- or L-configuration.
(3) Sucrose is a reducing sugar and lactose is a nonreducing sugar.

Accepted Answer

Statement (1) is true because sugars include both monosaccharides (single sugar molecules) and disaccharides (two sugar molecules bonded together). Statement (2) is also true; the D- or L-configuration of a monosaccharide is determined by the orientation of the hydroxyl group (-OH) on the highest-numbered chiral carbon. Statement (3) is false because sucrose is a nonreducing sugar (it cannot act as a reducing agent because it lacks a free aldehyde or ketone group), while lactose is a reducing sugar.

Question 7

Use the following to answer the questions below:
For each of the stereochemical descriptions, select from the response list an appropriate set of structural formulas. Responses may be used more than once or need not be used at all. 
-Epimers

Accepted Answer

The answer of Use the following to answer the questions...

Question 8

Use the following to answer the questions below:
In each of the following multiple-choice questions, characterize EACH of the three given statements as being TRUE or FALSE and then indicate the collective true-false status of the statements using the choices:
-Statements: (1) Mirror images of an achiral molecule are identical.
(2) All cyclic monosaccharides can exist in alpha- and beta-configurations.
(3) Reaction of an alcohol with a cyclic monosaccharide produces a glycoside.

Accepted Answer

(1) is true because mirror images of an achiral molecule are superimposable. (2) is true because all cyclic monosaccharides have an anomeric carbon that can exist in either the alpha- or beta-configuration. (3) is true because a glycoside is formed when an alcohol reacts with the anomeric carbon of a cyclic monosaccharide.

Question 9

Use the following to answer the questions below:
For each of the compound characterizations, select from the response list an appropriate structural formula. Responses may be used more than once or need not be used at all. 
-Eight stereoisomers exist for this compound.

Accepted Answer

The answer of Use the following to answer the questions...

Question 10

Use the following to answer the questions below:
For each of the disaccharides or polysaccharides, select from the response list the correct hydrolysis products. Responses may be used more than once or need not be used at all.

-Glycogen

Accepted Answer

Glycogen is a polysaccharide made up of many glucose molecules bonded together, so when it is hydrolyzed, it breaks down into individual glucose molecules.

Question 11

Use the following to answer the questions below:
In each of the following multiple-choice questions, characterize EACH of the three given statements as being TRUE or FALSE and then indicate the collective true-false status of the statements using the choices:
-Statements: (1) The biochemical basis for different types of blood is a system of polysaccharide markers attached to red blood cell membranes.
(2) Lactose intolerance is a genetic condition caused by excessive amounts of the enzyme lactase.
(3) Aspartame, the most used artificial sweetener, is an indigestible trisaccharide.

Accepted Answer

Statement 1 is false because blood types are determined by glycoproteins and glycolipids, not just polysaccharides. Statement 2 is false because lactose intolerance is due to a deficiency of lactase, not an excess. Statement 3 is false because aspartame is a dipeptide, not a trisaccharide.

Question 12

Use the following to answer the questions below:
For each of the disaccharides or polysaccharides, select from the response list the correct hydrolysis products. Responses may be used more than once or need not be used at all.

-Lactose

Accepted Answer

Lactose is composed of glucose and galactose monosaccharides. Therefore, hydrolysis of lactose will yield glucose and galactose as the hydrolysis products.

Question 13

Use the following to answer the questions below:
For each of the disaccharides or polysaccharides, select from the response list the correct hydrolysis products. Responses may be used more than once or need not be used at all.

-Starch

Accepted Answer

Starch is a polysaccharide made up of glucose molecules, so when it is hydrolyzed, the only product is glucose.

Question 14

Use the following to answer the questions below:
For each of the stereochemical descriptions, select from the response list an appropriate set of structural formulas. Responses may be used more than once or need not be used at all. 
-Diastereomers

Accepted Answer

The answer of Use the following to answer the questions...

Question 15

Use the following to answer the questions below:
For each of the disaccharides or polysaccharides, select from the response list the correct hydrolysis products. Responses may be used more than once or need not be used at all.

-Cellulose

Accepted Answer

Cellulose is composed of glucose monomers and can be hydrolyzed to produce glucose monomers only.

Question 16

Use the following to answer the questions below:
For each of the compound characterizations, select from the response list an appropriate structural formula. Responses may be used more than once or need not be used at all. 
-A chiral compound with two chiral centers

Accepted Answer

The answer of Use the following to answer the questions...

Question 17

Use the following to answer the questions below:
For each of the compound characterizations, select from the response list an appropriate structural formula. Responses may be used more than once or need not be used at all. 
-Four different L-stereoisomers exist for this compound.

Accepted Answer

The answer of Use the following to answer the questions...

Question 18

Use the following to answer the questions below:
For each of the stereochemical descriptions, select from the response list an appropriate set of structural formulas. Responses may be used more than once or need not be used at all. 
-Enantiomers

Accepted Answer

The answer of Use the following to answer the questions...

Question 19

Use the following to answer the questions below:
In each of the following multiple-choice questions, characterize EACH of the three given statements as being TRUE or FALSE and then indicate the collective true-false status of the statements using the choices:
-Statements: (1) Cellulose and amylose are glucose polymers that differ in the type of glycosidic linkage present.
(2) All monosaccharides are either aldoses or ketoses.
(3) Enantiomers can never be epimers.

Accepted Answer

(1) and (2) are true. (3) is false because enantiomers are always epimers.

Question 20

Use the following to answer the questions below:
For each of the compound characterizations, select from the response list an appropriate structural formula. Responses may be used more than once or need not be used at all. 
-A chiral compound with one chiral center

Accepted Answer

The compound with one chiral center is represented by a tetrahedral carbon atom with four different substituents attached to it. Option A shows such a structure. The other options do not have a tetrahedral carbon atom or do not have four different substituents attached to it.

Quiz 18: Carbohydrates

Use the following to answer the questions below: For each of the stereochemical descriptions, select from the response list an appropriate set of structural formulas. Responses may be used more than once or need not be used at all. -Optical isomers

Use the following to answer the questions below: For each of the disaccharides or polysaccharides, select from the response list the correct hydrolysis products. Responses may be used more than once or need not be used at all. -Sucrose

Use the following to answer the questions below: For each of the stereochemical descriptions, select from the response list an appropriate set of structural formulas. Responses may be used more than once or need not be used at all. -Mirror images

Use the following to answer the questions below: For each of the compound characterizations, select from the response list an appropriate structural formula. Responses may be used more than once or need not be used at all. -An achiral compound

Use the following to answer the questions below: For each of the stereochemical descriptions, select from the response list an appropriate set of structural formulas. Responses may be used more than once or need not be used at all. -Epimers

Use the following to answer the questions below: For each of the compound characterizations, select from the response list an appropriate structural formula. Responses may be used more than once or need not be used at all. -Eight stereoisomers exist for this compound.

Use the following to answer the questions below: For each of the disaccharides or polysaccharides, select from the response list the correct hydrolysis products. Responses may be used more than once or need not be used at all. -Glycogen

Use the following to answer the questions below: For each of the disaccharides or polysaccharides, select from the response list the correct hydrolysis products. Responses may be used more than once or need not be used at all. -Lactose

Use the following to answer the questions below: For each of the disaccharides or polysaccharides, select from the response list the correct hydrolysis products. Responses may be used more than once or need not be used at all. -Starch

Use the following to answer the questions below: For each of the stereochemical descriptions, select from the response list an appropriate set of structural formulas. Responses may be used more than once or need not be used at all. -Diastereomers

Use the following to answer the questions below: For each of the disaccharides or polysaccharides, select from the response list the correct hydrolysis products. Responses may be used more than once or need not be used at all. -Cellulose

Use the following to answer the questions below: For each of the compound characterizations, select from the response list an appropriate structural formula. Responses may be used more than once or need not be used at all. -A chiral compound with two chiral centers

Use the following to answer the questions below: For each of the compound characterizations, select from the response list an appropriate structural formula. Responses may be used more than once or need not be used at all. -Four different L-stereoisomers exist for this compound.

Use the following to answer the questions below: For each of the stereochemical descriptions, select from the response list an appropriate set of structural formulas. Responses may be used more than once or need not be used at all. -Enantiomers

Use the following to answer the questions below: For each of the compound characterizations, select from the response list an appropriate structural formula. Responses may be used more than once or need not be used at all. -A chiral compound with one chiral center