paper 1: Monomers, Polymers: Carbohydrates Flashcards
define a monomer
smaller, soluble molecules from which larger molecules are made
define a polymer
molecules made from many similar monomers joined together
why are lipids not polymers
they don’t contain similar monomers
what is the monomer and polymer of a carbohydrate called
monomer: monosaccharide
polymer: polysaccharide
what is the monomer and polymer of a protein called
monomer: amino acid
polymer: polypeptide
what is the monomer and polymer of DNA/RNA called
monomer: nucleotide
polymer: polynucleotide
describe what happens during a condensation reaction
a condensation reaction joins two molecules together with the formation of a chemical bond and involves the elimination of a water molecule.
describe what happens during a hydrolysis reaction
a hydrolysis reaction breaks a chemical bond between 2 molecules and involves the use of a water molecule.
what is a monosaccharide and name 3 examples.
monomers from which larger carbohydrates are made.
glucose, fructose, galactose
describe a disaccharide and give 3 examples
2 monosaccharides joined together by a glycosidic bond which form during a condensation reaction
maltose, sucrose, lactose
describe a polysaccharide and give 3 examples
formed by the condensation of many repeating monosaccharides
starch, glycogen, cellulose
what is an isomer
molecules with the same chemical formula but different structural formula.
what is the chemical formula for glucose
C6H12O6
name the two isomers of glucose
alpha glucose, beta glucose
draw the diagram of an alpha glucose molecule
Draw the diagram of a beta glucose molecule
describe the difference between the two isomers of alpha glucose and beta glucose
the position of the hydrogen and hydroxyl groups on the carbon 1 are inverted.
when two glucose molecules join together in a condensation reaction what forms
maltose and water
when a glucose molecule and a fructose molecule join together in a condensation reaction what is produced
sucrose and water
when a glucose molecule and a galactose molecule join together in condensation reaction what is produced
lactose and water
draw a diagram of a condensation reaction of 2 glucose molecules
draw a diagram showing a hydrolysis reaction of 2 glucose molecules
which monosaccharide is glycogen and starch made out of
alpha glucose
which monosaccharide is cellulose made from
beta glucose
draw a diagram of the polysaccharides starch and glycogen
draw a diagram of the polysaccharide cellulose
how is the structure of cellulose different from the structure of glycogen and starch
in the cellulose polymer the monomers face in alternate directions rather than all the same way like a starch polymer.
explain why the structure of the polysaccharide chains of starch/ glycogen and cellulose are different
starch and glycogen are polymers of alpha glucose whereas cellulose is a polymer of beta glucose.
in beta glucose the position of the hydrogen and hydroxyl groups on the carbon 1 are inverted
explai why it is useful that starch is branched
- the branches provide more ends for enzymes to hydrolyse starch into glucose
- so glucose is released faster in respiration
how do the properties of starch relate to their function
coiled into a helix: compact so can fit a lot in a small space
insoluble: doesn’t effect osmosis
large: cannot diffuse across cell membrane and out of cells
highly branched: provides a larger surface area so can be more rapidly hydrolysed so glucose can be released more readily for respiration.
how do the properties of glycogen relate to their function
coiled into a helix: compact so can fit a lot in a small space
insoluble: doesn’t effect osmosis
large: cannot diffuse across cell membrane and out of cells
highly branched: provides a larger surface area so can be more rapidly hydrolysed so glucose can be released more readily for respiration.
describe the structure of cellulose
many beta-glucose molecules joined together, forming long, straight and unbranched chains of cellulose
how do the properties of cellulose relate to its function
- long, straight and unbranched chains of beta glucose
- linked together by many hydrogen bonds to form microfibrils
- provide strength and rigidity to plant cell walls.
summarise the differences and similarities between cellulose, starch and glycogen
name the three tests for carbohydrates
benedicts test for reducing sugars, benedicts test for non-reducing sugar, iodine solution test for starch.
describe the benedicts test for reducing sugars
- add benedicts solutions to sample and heat to 95 degrees
- a colour change from blue to a brick red shows a positive result
- if no change in colour then a non-reducing sugar is present
suggest a way, other than comparing colour changes, in which different concentrations of reducing sugar could be estimated
- filter and dry precipitate in each sample
- find the mass
- the higher the mass of the precipitate the more reducing sugar is present
describe the test for non-reducing sugar (sucrose)
- do benedicts test and if stays blue
- boil a fresh sample with acid
- then neutralise with **alkali **
- heat with benedicts solution at 95 degrees
- if **non-reducing sugar **is present, there will be a colour change from blue to orange/ red
describe the test for starch
- add iodine solution to sample
- colour will change from orange to blue/black if starch is present
what is the function of glycogen
the main glucose store in animals
