1.4 Starch, glycogen and cellulose Flashcards
where is starch found?
in plants as small grains
-large amounts in seeds/storage organs
what is starch made up of?
chains of alpha glucose monosaccharides
how is starch made?
condensation reactions
glycosidic bonds
what is starches main function?
energy storage
how is starches structure suited for energy storage?
-insoluble- doesn’t affect water potential
=water not drawn into cell by osmosis
-large and insoluble
=doesn’t diffuse out of cells
-compact
=can be stored in a small space
-forms alpha glucose when hydrolysed
=easily transported, readily used in respiration
-branched form has many ends
=ends can be simultaneously acted on my enzymes
=glucose molecules released rapidly
what is the structure of starch chains?
can be branched or unbranched
-unbranched chain wound into coil
where is glycogen found?
animals
bacteria
how does glycogen compare to starch?
similar
-shorter chains, more branched
how is glycogen stored in animals?
stored as granuels
in muscle/liver
what is the main function of glycogen?
storage
how is glycogen structure suitable for storage?
-insoluble
=doesnt draw water into cells by osmosis
=doesnt diffuse out of cells
-compact
=lots can be stored in small space
-more highly branched than starch
=more ends can be simultaneously acted on my enzymes
=glucose molecules released rapidly
=important as animals have higher metabolic, respiratory rate than plants (more active)
what is cellulose made out of?
monomer beta glucose
where is cellulose found?
major component of plant cell wall
what is the main function of cellulose?
support and rigidy
how is cellulose structure suitable for support and rigidy?
-made up of beta glucose
=straight unbranched chains
=parallel= cross linked by hydrogen bonds= collective strength
-grouped into microfibrils then fibres
=more strength
