Chapter 17, Problem 17.4E

Interpretation Introduction

(a)

Interpretation:

Whether table sugar is a monosaccharide, disaccharide, or polysaccharide is to be stated.

Concept introduction:

On the basis of the structural differences carbohydrates are classified into three parts.

Monosaccharide: They are the polyhydroxy aldehydes or ketones containing only one aldehyde or ketone unit. For example: glucose and fructose.

Disaccharide: They are the polyhydroxy aldehydes or ketones containing two aldehyde or ketone units. For example: Sucrose, lactose.

Polysaccharide: They are the polyhydroxy aldehydes or ketones containing more than two aldehyde or ketone units. For example: Cellulose, starch.

Answer to Problem 17.4E

Table sugar is a disaccharide.

Explanation of Solution

Table sugar is also known as sucrose. Sucrose on hydrolysis gives two monosaccharides, glucose and fructose which are linked through a glycosidic linkage. This shows that sucrose or table sugar is a disaccharide.

Conclusion

Table sugar is a disaccharide.

Interpretation Introduction

(b)

Interpretation:

Whether the given carbohydrate is a monosaccharide, disaccharide, or polysaccharide is to be stated.

Concept introduction:

On the basis of the structural differences carbohydrates are classified into three parts.

Monosaccharide: They are the polyhydroxy aldehydes or ketones containing only one aldehyde or ketone unit. For example: glucose and fructose.

Disaccharide: They are the polyhydroxy aldehydes or ketones containing two aldehyde or ketone units. For example: Sucrose, lactose.

Polysaccharide: They are the polyhydroxy aldehydes or ketones containing more than two aldehyde or ketone units. For example: Cellulose, starch.

Answer to Problem 17.4E

The given carbohydrate is an example of monosaccharide.

Explanation of Solution

The structural formula of the given carbohydrate is shown below.

Figure 1

The above structure of carbohydrate shows that there is no glycosidic linkage through which another carbohydrate is linked. Therefore, the above carbohydrate is a monosaccharide.

Conclusion

The carbohydrate shown in Figure 1 is an example of monosaccharide.

Interpretation Introduction

(c)

Interpretation:

Whether starch is a monosaccharide, disaccharide, or polysaccharide is to be stated.

Concept introduction:

On the basis of the structural differences carbohydrates are classified into three parts.

Monosaccharide: They are the polyhydroxy aldehydes or ketones containing only one aldehyde or ketone unit. For example: glucose and fructose.

Disaccharide: They are the polyhydroxy aldehydes or ketones containing two aldehyde or ketone units. For example: Sucrose, lactose.

Polysaccharide: They are the polyhydroxy aldehydes or ketones containing more than two aldehyde or ketone units. For example: Cellulose, starch.

Answer to Problem 17.4E

Starch is a polysaccharide.

Explanation of Solution

Starch is the polymeric form of D-glucose. Starch on hydrolysis gives a large number of molecules of glucose which are linked by glycosidic linkage. Therefore, starch is a polysaccharide. Starch is present in plants.

Conclusion

Starch is an example of polysaccharide.

Interpretation Introduction

(d)

Interpretation:

Whether fructose is a monosaccharide, disaccharide, or polysaccharide is to be stated.

Concept introduction:

On the basis of the structural differences carbohydrates are classified into three parts.

Monosaccharide: They are the polyhydroxy aldehydes or ketones containing only one aldehyde or ketone unit. For example: glucose and fructose.

Disaccharide: They are the polyhydroxy aldehydes or ketones containing two aldehyde or ketone units. For example: Sucrose, lactose.

Polysaccharide: They are the polyhydroxy aldehydes or ketones containing more than two aldehyde or ketone units. For example: Cellulose, starch.

Answer to Problem 17.4E

Fructose is a monosaccharide.

Explanation of Solution

Hydrolysis of sucrose produces glucose and fructose which do not undergo further hydrolysis. Therefore, fructose comes under the category of monosaccharide.

Conclusion

Fructose is an example of monosaccharide.

Interpretation Introduction

(e)

Interpretation:

Whether cellulose is a monosaccharide, disaccharide, or polysaccharide is to be stated.

Concept introduction:

On the basis of the structural differences carbohydrates are classified into three parts.

Monosaccharide: They are the polyhydroxy aldehydes or ketones containing only one aldehyde or ketone unit. For example: glucose and fructose.

Disaccharide: They are the polyhydroxy aldehydes or ketones containing two aldehyde or ketone units. For example: Sucrose, lactose.

Polysaccharide: They are the polyhydroxy aldehydes or ketones containing more than two aldehyde or ketone units. For example: Cellulose, starch.

Answer to Problem 17.4E

Cellulose is a polysaccharide.

Explanation of Solution

Cellulose is a polymeric form of D-glucose because cellulose on hydrolysis gives a large number of glucose as monosaccharide. Each glucose is linked with $\beta -1,4$-glycosidic linkage. This type of linkage allows more packed and long chain polymeric structure of cellulose. Therefore, cellulose is an example of polysaccharide.

Conclusion

Cellulose on hydrolysis gives a large number of molecules of glucose. As a result, cellulose is a polysaccharide.

Interpretation Introduction

(f)

Interpretation:

Whether the given carbohydrate is a monosaccharide, disaccharide, or polysaccharide is to be stated.

Concept introduction:

On the basis of the structural differences carbohydrates are classified into three parts.

Monosaccharide: They are the polyhydroxy aldehydes or ketones containing only one aldehyde or ketone unit. For example: glucose and fructose.

Disaccharide: They are the polyhydroxy aldehydes or ketones containing two aldehyde or ketone units. For example: Sucrose, lactose.

Polysaccharide: They are the polyhydroxy aldehydes or ketones containing more than two aldehyde or ketone units. For example: Cellulose, starch.

Answer to Problem 17.4E

The given carbohydrate is a disaccharide.

Explanation of Solution

The structural formula of the given carbohydrate is shown below.

Figure 2

The above structure of carbohydrate shows that two monosaccharides are linked to each other through glycosidic linkage and results in the formation of a disaccharide. Therefore, the above carbohydrate is a disaccharide.

Conclusion

The carbohydrate shown in Figure 2 is an example of disaccharide.

Interpretation Introduction

(g)

Interpretation:

Whether glycogen is a monosaccharide, disaccharide, or polysaccharide is to be stated.

Concept introduction:

On the basis of the structural differences carbohydrates are classified into three parts.

Monosaccharide: They are the polyhydroxy aldehydes or ketones containing only one aldehyde or ketone unit. For example: glucose and fructose.

Disaccharide: They are the polyhydroxy aldehydes or ketones containing two aldehyde or ketone units. For example: Sucrose, lactose.

Polysaccharide: They are the polyhydroxy aldehydes or ketones containing more than two aldehyde or ketone units. For example: Cellulose, starch.

Answer to Problem 17.4E

Glycogen is a polysaccharide.

Explanation of Solution

Glycogen is a polymeric form of D-glucose which on hydrolysis gives glucose units. Each glucose unit is linked by $\alpha -1,4$-glycosidic linkage. Therefore, glycogen is an example of polysaccharide. Glycogen is present in the muscles and liver of animals.

Conclusion

Glycogen on hydrolysis gives a large number of molecules of glucose. As a result, glycogen is a polysaccharide.

Interpretation Introduction

(h)

Interpretation:

Whether amulose is a monosaccharide, disaccharide, or polysaccharide is to be stated.

Concept introduction:

On the basis of the structural differences carbohydrates are classified into three parts.

Monosaccharide: They are the polyhydroxy aldehydes or ketones containing only one aldehyde or ketone unit. For example: glucose and fructose.

Disaccharide: They are the polyhydroxy aldehydes or ketones containing two aldehyde or ketone units. For example: Sucrose, lactose.

Polysaccharide: They are the polyhydroxy aldehydes or ketones containing more than two aldehyde or ketone units. For example: Cellulose, starch.

Answer to Problem 17.4E

Amylose is a polysaccharide.

Explanation of Solution

Amylose is a polymeric form of $\alpha -$ D-glucose because amylose on hydrolysis gives a large number of glucose units. Each glucose is linked with $\alpha -1,4$-glycosidic linkage. This type of linkage allows more packed and long chain polymeric structure of amylose. Therefore, amylose is an example of polysaccharide.

Conclusion

Amylose on hydrolysis gives a large number of glucose units. As a result, amylose is a polysaccharide.