starch, glycogen and cellulose Flashcards
what is starch?
a polysaccharide that is found in many parts of a plant in the form of small grains
what type of glucose is starch and glycogen made from?
alpha glucose
how are alpha glucose monosaccharides linked into chains?
by glycosidic bonds that are formed by condensation reactions
what shape does the chain form in starch and glycogen?
alpha helix
where do hydrogen bonds form in starch and glycogen?
between points on one shape
which has more branches, starch or glycogen?
glycogen which makes it more compact and this is useful so that you can store more glucose in a smaller space
what is the main role of starch?
energy storage in plants
what benefits does starch and glycogen being large and insoluble molecules have?
-doesn’t affect water potential so no osmotic effect =no burst
-molecules retained in cell as they cannot pass across the cell membrane
how are starch and glycogen compact molecules?
-helix structure makes it compact so many glucose molecules stored in a small space
-branches
in starch and glycogen what are the benefits of branches?
-makes molecules more compact so more glucose stored in smaller space
-provide lots of spaces where enzymes can act to break down the molecule so that glucose can be released quickly for respiration, so energy is released (ATP made)
what is the role of glycogen?
energy storage in animals
why does glycogen being more branched than starch help the role of glycogen?
more branched = more area for enzymes to act- therefore molecules can be rapidly broken down to form glucose monomers, which are used in respiration to release energy (ATP made)
animals have a higher metabolic rate and therefore higher respiration rate than plants because they are more active and need more energy from ATP
which type of glucose is cellulose made from?
beta
what shape does the chain form in cellulose?
straight
where do hydrogen bonds form between in cellulose?
between different chains
