Polysaccharides Flashcards
What is a polysaccharide?
Polymer of monosaccharides formed by many condensation reactions
What are the properties of polysaccharides?
Insoluble so don’t affect osmosis
Compact so can be stored in a small place in the cell
Easily hydrolysed to release the glucose for respiration
What is glucose?
Main source of energy in cells
Must be stored in an appropriate form
Soluble in water = would affect osmosis within the cell
Overcome by converting glucose into storage polysaccharides
What are the 4 examples of polysaccharides?
Starch
Glycogen
Cellulose
Chitin
What are 2 examples of energy storage polysaccharides?
Starch - found in plants
Glycogen - found in liver and muscles
What are 2 examples of structural function polysaccharides?
Cellulose
Chitin
What is the function of starch?
Energy storage in plants
What are the 2 different molecules that make up starch?
Amylose
Amylopectin
What is starch?
Glucose energy storage polysaccharide in plant cells
Describe the structure of starch
Made up of thousands of alpha glucose monomers
Describe the structure of amylose
Straight chained
Helical polymer
Alpha 1-4 glycosidic bonds
Unbranched
Describe the structure of amylopectin
Branched polymer
Alpha 1-4 and 1-6 glycosidic bonds
What is the function of glycogen?
Energy storage in animals
What is glycogen?
Animals energy storage polysaccharide found inside liver and muscle cells
Describe the structure of glycogen
Alpha 1-4 and 1-6 glycosidic bonds
Highly branched
How does the structure of glycogen relate to its function?
Highly branches
Enables the rapid hydrolysis of glucose molecules
From the ends of branches to be used in respiration
What is the function of cellulose?
Important in plants as a structural carbohydrate
Important component of the plant cell all
Gives plant cell rigidity as the cellulose cell is inelastic
Has a high tensile strength to prevent plant cell from bursting
Describe the structure of cellulose
Consists of many beta glucose molecules joined by beta 1-4 glycosidic bonds
Alternate glucose molecules rotate 180 degrees
Allows hydrogen bonds between parallel chains, forming microfibrils
Many microfibrils form a strong cellulose bundle
What is the function of chitin?
Found in the exoskeleton of insects, crustaceans, arachnids and cell wall of fungi
Describe the structure of chitin
Composed of many beta glucose molecules joined together with 1-4 glycosidic bonds
Contains acetyl amine group bonded to carbon 2 of the beta glucose monosaccharide
Beta glucose molecules are inverted to form the 1-4 glycosidic bonds
Chitin chains are straight which are parallel to each other
Has hydrogen bonds forming cross-links between the chains
Cross-linked chitin chains bundle together to form stronger microfibrils
What are the properties of chitin?
Strong - used to give strength to exoskeleton
Waterproof - helps insects prevent water loss from their body
Lightweight - allows to insects to carry exoskeleton
