polysaccharides Flashcards
how are polysaccharides formed
many monosaccharides units joined by condensation reactions that form glycosidic bonds
oligosaccharides
molecules with 3-10 sugar units
true polysaccharides
molecules with more than 11 sugar units or 11
why do polysaccharides make good storage molecules
-they can form very compact molecules so large numbers can be stored in a cell
-glycosidic bonds broken down easily rapid release of energy
-not soluble in water so dont disturb osmotic potential
how is a glycosidic bond broken
by a hydrolisis reaction
what is hydrolisis
the opposite of condensation where water is added
what happens when polysaccharides break down
they turn into smaller and shorter chains and eventually a simple sugar aka a monosaccharide
where does hydrolisis reaction take place
in the gut
-muscle and liver cells when carbs stored are broken down to release sugars for use in cellular respiration
what carbon bond is hydrolisis of alpha glucose and alpha glucose
1-4 bond
why is starch important in plants
sugars produced by photosynthesis rapidly converted to starch which is insoluble and compact
what monosaccharide is starch made of
alpha glucose
what 2 mixtures is starch made of
amylose
amylopectin
what is amylose
a branched polymer made of between 200 to 5000 glucose molecules
what happens to amylose as the chain lengthens
it spirals making it more compact for storage
what is amylopectin
branched polymer of glucose molecules
whats special about amylopectin
branching chains have terminal glucose molecules which can be broken of easily for quick energy
what carbon bond does amylose have
1-4 pure alpha glucose bonds which are why they are unbranched
what carbon bonds does amylopectin have
1-4 but a few 1-6 bonds which is why the molecule is branching which change the properties of the molecule
why are starchy foods good for sports and athletes
starch has a combination of straight chained and branched chain molecules
amylopectin releases glucose rapidly and amylose releases it slowly to keep you going longer
what energy store of carbs is found in animals
glycogen
what is glycogen an important storage molecule in (2)
fungi and animals
glycogens chemical structure
similar to amylopectin molecules and made up of lots of alpha glucose units
physical structure of glycogen
its has more 1-6 bonds giving it many side branches so it can be broken down rapidly
-this makes it an ideal source for glucose in active tissues with high cellular respiration rates
starch in plants
main source of energy
