POLYSACCHARIDES Flashcards
What are polysaccharides?
Polysaccharides contain a large number of monosaccharide units joined together by glycosidic linkages and act as food storage or structural materials.
What is the most commonly encountered type of carbohydrate in nature?
Polysaccharides.
What are the main functions of polysaccharides?
They mainly act as food storage or structural materials.
What is starch?
Starch is the main storage polysaccharide of plants and an important dietary source for humans.
Where is starch commonly found?
In cereals, roots, tubers, and some vegetables.
What is starch made of?
Starch is a polymer of α-glucose and consists of two components: amylose and amylopectin.
What are the two components of starch?
Amylose and amylopectin.
What is amylose?
Amylose is the water-soluble component of starch, constituting about 15-20% of it.
What is the structure of amylose?
Amylose is a long, unbranched chain with 200-1000 α-D-(+)-glucose units held together by C1–C4 glycosidic linkages.
What is amylopectin?
Amylopectin is the water-insoluble component of starch, making up about 80-85% of it.
Is amylopectin soluble in water?
No, amylopectin is insoluble in water.
What type of polymer is amylopectin?
Amylopectin is a branched-chain polymer of α-D-glucose units.
How is the main chain of amylopectin formed?
The main chain is formed by C1–C4 glycosidic linkages.
How does branching occur in amylopectin?
Branching occurs through C1–C6 glycosidic linkages.
Where is cellulose found?
Cellulose occurs exclusively in plants and is the most abundant organic substance in the plant kingdom.
What is the primary function of cellulose in plants?
It is a predominant constituent of the cell wall of plant cells.
What type of polysaccharide is cellulose?
Cellulose is a straight-chain polysaccharide composed only of β-D-glucose units.
How are the glucose units in cellulose linked?
They are joined by glycosidic linkages between C1 of one glucose unit and C4 of the next glucose unit.
How are carbohydrates stored in the animal body?
Carbohydrates are stored in the animal body as glycogen.
What is another name for glycogen? Why?
Glycogen is also known as animal starch because its structure is similar to amylopectin but more highly branched.
Where is glycogen found in the human body?
Glycogen is present in the liver, muscles, and brain.
What happens when the body needs glucose?
Enzymes break down glycogen into glucose.
Besides animals, where else is glycogen found?
Glycogen is also found in yeast and fungi.
