Polysaccharides Flashcards
What are polysaccharides used for?
Energy store
Structural components of cells
What are polysaccharides?
3+ units of sugar joined together
What are polysaccharides made up of entirely one kind of monosaccharide called?
Homopolysaccharides
What are polysaccharides called that are made up of more that one type of monosaccharide?
Heteropolysaccharides
What is the reaction that breaks polysaccharides into di/monosaccharides?
Hydrolysis reaction
Describe the structure of starch.
Polymer of alpha glucose molecules with 1-4 glycosidic bonds linking the molecules together
The chains coil up into a spring shape
What are the 2 types of starch?
Amylose
Amylopectin
Describe the structure of amylose.
Long, unbranched chains of α-glucose
Angles of glyosidic bonds makes it a coiled structure - this makes it compact and good for storage
Amylose is insoluble so does not effect water potential
Contain 1-4 glyosidic bonds
Describe the structure of amylopectin.
Long, unbranched chains of α-glucose
Has side branches which allows enzyme to hydrolyse bonds more easily - glucose is released quickly
Amylopectin is insoluble so does not effect water potential inside a cell
Contain 1-4 glyosidic bonds
Branches with 1-6 glyosidic bonds
What are the properties and functions of starch?
- Carbohydrate storage molecule in plants
- Stored as intracellular starch grains in plasmids
- Produced from glucose during photosynthesis
- Source of carbon for producing other molecules
- Insoluble in water due to its size
Describe the structure of glycogen.
Insoluble carbohydrate, storage molecule in animals, polysaccharide of alpha glucose, 1-4 and 1-6 glycosidic bonds, branched to enable easy hydrolysis
What are the properties of glycogen?
- Main energy storage material in animals
- Animals store excess glucose as glycogen
- Stored as small granules in muscle and liver
- Less dense and more soluble than starch
Describe the structure of cellulose.
Long, unbranched chains of β-glucose
Glyosidic bonds makes a straight chained molecule
Cellulose chains are linked together by hydrogen bonds - forming microfibrils
Microfibrils are further bunched together to form macrofibrils
The arrangement of OH and H groups on the C1 of the beta glucose means that adjacent glucose molecules only join if alternate molecules are inverted
What are the properties of cellulose?
- Major component of cell walls in plants
- Linked via hydrogen bonds to form strong fibres called microfibrils due to the high number of OH groups on the outside of the cellulose chains
- Bundles of microfibrils are also cross linked by hydrogen bonds
