Biological molecules: Starch, Glycogen And Cellulose Flashcards
What is starch made of?
Chains of alpha glucose monosaccharides linked by glycosidic bonds that are formed by condensation reactions.
How is the helix of a starch molecule held in place?
There are hydrogen bonds between the OH groups as they are pointing inwards
What are the two types of starch?
Amylose and amylopectin
For amylopectin,
What monomer is it made from?
What are the bonds between the monomers?
What is it’s shape?
- alpha glucose
- 1,4 glycosidic bond
- helix shape
For amylopectin,
What monomer is it made from?
What are the bonds between the monomers?
What is it’s shape?
- alpha glucose
- 1,4 and 1,6 glycosidic bonds
- helix shape with branches
What are the 5 ways the structure of starch allows its main role to be energy storage
- its insoluble so doesn’t affect water potential so water’s not drawn into cells by osmosis
- its largeness and insolubility stops it diffusing out of cells
- its compact so a lot can be stored in a small space
- when hydrolysed it forms alpha glucose which is both easily transported and readily used in respiration
- amylopectin ( the branched form) has many ends which can be acted upon by enzymes simultaneously meaning glucose monomers are released very rapidly
What cells is starch never found in?
Animal cells
Where is glycogen found?
Animal and bacterial cells ( never plant cells)
How is the structure of glycogen different to starch?
Its more highly branched but has shorter chains than starch
How and where is glycogen stored in animals?
As small granules in the muscles and liver
Why is the mass of carbohydrate stored in animals relatively small?
Because fat is the main storage molecule in animals
Why is the structure of glycogen suited for its storage?
- its insoluble so doesn’t draw water into cells by osmosis and doesn’t diffuse out of cells
- its compact so a lot of it can be stored in a small space
- its more highly branched than starch and so has more ends that can be acted on simultaneously by enzymes and so is more rapidly broke down into glucose monomers which are used in respiration. Important to animals that have a higher metabolic rate and so higher respiratory rate than animals as they are more active
What monomers make up cellulose?
Beta glucose monomers
What cells is cellulose found in?
Plant cells
What is the name of the bonds between the monomers of cellulose
Beta 1,4 bonds