Chapter 24.2, Problem 14LC

(a)

Interpretation Introduction

Interpretation: The source of starch is to be stated.

Concept Introduction: Starch is a polysaccharide formed by linking numerous glucose monomers.

Answer to Problem 14LC

Plants are the source of starch.

Explanation of Solution

Starch comes from a variety of plants, which use this polysaccharide as a primary energy source. Potatoes, rice, wheat, cassava, corn, and peas are the most common sources of starch.

(b)

Interpretation Introduction

Interpretation: The source of cellulose is to be stated.

Concept Introduction: Cellulose is a polysaccharide made up of numerous glucose monomers linked together.

Answer to Problem 14LC

The sources of cellulose include cotton and plant structural materials.

Explanation of Solution

Cellulose is the most abundant type of biological molecule found on the earth. Cotton and other plant materials that serve as structural components, such as wood and other plant cell walls, are the main source of cellulose.

(c)

Interpretation Introduction

Interpretation: The source of glycogen is to be stated.

Concept Introduction: Glycogen is a polysaccharide formed by the linking of numerous glucose monomers.

Answer to Problem 14LC

Liver and animal muscle cells are the sources of glycogen.

Explanation of Solution

Although glycogen, starch, and cellulose all contain the same monomer units, how glucose is linked is distinct in these three polysaccharides. The liver and muscle cells of animals are the primary storage sites for glycogen. Hence, these organs are the main source of glycogen.