carbohydrates- monomers and polymers Flashcards
what are monomers
small basic molecular units
what are polymers
large complex molecules composed of long chains of monomers joined together
are carbs monomers or polymers
mostly polymers
examples of monomers
monosaccharides, amino acids, and nucleotides
what elements are contained in all carbs?
C,H,O
what is glucose?
a hexose sugar, a monosaccharide with six carbon atoms in each molecule
how many types of glucose are there
2- alpha and beta
- they’re isomers
what are isomers in terms of glucose
molecules with the same molecular formula as each other but with the atoms connected in a different way
what is a condensation reaction
when two molecules join together with the formulation of a new chemical bond.
- a water molecule is released when a bond it formed
what bonds are monosaccharides bound by
condensation reactions, glycosidic bonds
what is a disaccharide
two monosaccharides are joined together
what is sucrose made from
one glucose and one fructose
what is lactose made from
glucose and galactose
how can polymers be broken down
hydrolysis reactions
how does hydrolysis happen
adding a water molecule to break up the polymer into monomers
Test for reducing sugars
- add Benedict’s reagent
- heat it until the water bath, until solution boils
- if positive a coloured precipitate is shown
- blue, green, yellow, orange, red
- the higher the concentration the further the colour change goes
how can you compare the amount of reducing sugar in different precipitates
filter the solution and weigh the precipitate
test for non reducing rugars
- add dilute hydrochloric acid
- boil it
- neutralise the solution with sodium hydrogencarbonate
- then carry out the test for reducing sugars
- same results as reducing sugar
in what form is excess glucose stored in plants
starch
what happens when plants need to use glucose from their stores
it breaks down the starch to produce more glucose
amylose overview
- a long unbranched chain of alpha glucose
- the angles of the glycosidic bonds give it its coiled structure almost like a cylinder
- compact and good for storage because it can fit more into a small place
what two polysaccharides of alpha glucose is starch made out of
amylose and amylopectin
amylopectin overview
- long unbranched chain of alpha glucose
- side branches allow the enzymes that break down the glycosidic bonds can get to the bonds easily
- means that glucose can be released easily
how does starch effect water potential
-starch insoluble in water so doesn’t effect water potential
- doesn’t cause water to enter cells by osmosis which would make them swell, this makes it good for storage
