Unit 1

Created by

Nicole Chideya

Cards (62)

what is a monomer
small units that join together to form larger molecules
what is a polymer
large molecules made from many monomers joined together
what is the name of this molecule?
alpha glucose
what is the name of this molecule? 
beta glucose
what is the name of the bond between monosaccharides
glycosidic
what monomers join to make sucrose
glucose and fructose
what monomers join to make maltose
two alpha glucose
what monomers join to form lactose
glucose and galactose
describe the properties of starch
large to cannot leave the cell
helical so compact
insoluble so doesn't affect water potential
describe the structure of amylose
polymer of alpha glucose
has 1-4 glycosidic bonds
has helical shape
describe the structure of amylopectin
polymer of alpha glucose
has 1-4 and 1-6 glycosidic bonds
branched
what is the advantage of amylopectin being branched
provides a larger surface area for enzymes to attach
so starch can be readily hydrolysed into glucose
describe the structure of proteins
primary - amino acids joined together by peptide bonds via condensation

secondary - the polypeptide chain folds into alpha helixes and beta pleated sheets they have hydrogen bonding
tertiary - 3d shape with hydrogen and ionic bonding and disulphide bridges
quaternary - two or more polypeptide chains
state how ATP is a good source of energy
releases energy instantaneously
releases energy in small amounts
phosphorylates other molecules to make them more reactive
can be resynthesised rapidly
does not leave cells
explain the importance of water
a metabolite in condensation , hydrolysis and respiration
a solvent so allows transport of substances
large latent heat of vaporisation - provides a cooling effect
high specific heat capacity - buffers temperature changes
cohesion - produces surface tension so small animals can walk on water
cohesion so supports columns of water in plants
label the groups in the amino acid
.
A) carboxyl group
B) amine group
define the term isomers
molecules with the same molecular formula but different structure
relate the structure and function of triglycerides
insoluble hydrocarbon chain - has no affect on water potential of cells
large molecules - large chemical energy store
high ratio of carbon to hydrogen bonds in fatty acid tails - lots of energy released when respired + water released when respired ( useful for desert animals )
low mass to energy ratio - low density so lots of energy stored with low mass + useful as a buoyancy aid as lower density than water
relate the structure of DNA to its function
sugar phosphate backbone and many hydrogen bonds provide stability
long polynucleotide chain stores lots of genetic information
weak hydrogen bonds break so strands separate for replication
many hydrogen bonds stabilise the helix
double stranded for semi conversative replication
antiparallel strands for complementary base pairing
describe semi conservative replication of DNA
double helix unwinds
DNA helicase breaks hydrogen bonds between base pairs in the polynucleotide strands
each strand acts as a template
free nucleotides form complementary base pairs with the single stranded template strand
DNA polymerase joins adjacent nucleotides causing the formation of phosphodiester bonds
hydrogen bonds reform
semi conservative as each replicated DNA double helix contains one old strand and one new strand
why is ATP useful
releases energy in small amounts so energy isnt wasted
quickly broken down so energy is released quickly
ATP cannot pass out of the cell so cells have an immediate supply of energy
phosphorylates other compounds to make them more reactive by lowering the activation energy
Describe the biochemical tests you would use to confirm the presence of lipid 
add / dissolve in ethanol
add water and mix
positive result : white emulsion
Describe the biochemical tests you would use to confirm the presence of non-reducing sugar
add benedicts reagent
solution remains blue
boil with acid then neutralise with alkali
heat with benedicts reagent
positive result : brick red precipitate
Describe the biochemical tests you would use to confirm the presence of protein in a sample
add biurets reagent
positive result : lilac
Describe two differences between the structure of a tRNA molecule and the structure of an mRNA molecule.
tRNA is clover shaped but mRNA is linear
tRNA has an amino acid binding site but mRNA doesnt
tRNA has anticodons mRNA has codons
tRNA has hydrogen bonding mRNA doesnt
why are lipids not polymers
they are not made from repeating monomers
why is the function of starch
energy store in plants
what is the function of glycogen
energy store in animal cells
describe the structure of glycogen
polysaccharide of alpha glucose
1-4 and 1-6 glycosidic bonds
highly branched
relate the structure and function of glycogen
branched - more ends for enzymes to attach for faster hydrolysis so glucose can be released for respiration to make ATP
large - cannot leave the cell
insoluble - water potential of the cell is not affect
what is the function of cellulose
strength and structural support to plant and algal cell walls
name a non reducing sugar
sucrose
suggest a method to measure the quantity of sugar in a solution
carry out benedicts test
filter then dry the precipitate
measure mass using a balance
suggest another method to measure the quantity of sugar in a solution
make a series dilution of different sugar concentrations
heat each dilution with the same volume of benedicts reagent
ensure the volume of each dilution is the same
use a colorimeter to measure absorbance of each known concentration
plot calibration curve - concentration on x axis and absorbance of y axis
repeat the benedicts test with an sample of unknown concentration and measure absorbance
read off the calibration curve to find the concentration of the unknown sample
describe the biochemical test for starch
add iodine dissolved in potassium iodide
shake
positive result : brown to blue-black
unsaturated hydrocarbons have... 
one or more carbon to carbon double bonds
how do enzymes act as biological catalysts
lowers activation energy of a reaction
speeds up the rate of reaction
describe the induced fit model
active site is not completely complementary to substrate
substrate binds to active site
active site moulds around the substrate
enzyme-substrate complex forms
puts strain on bonds in substrate
Describe and explain the effect of enzyme concentration on the rate of enzyme-controlled reactions
as enzyme conc increases rate of reaction increases
enzyme concentration is a limiting factor as there may be excess substrate
more enzymes so more available active sites
more enzyme-substrate complexes form
as a certain point the rate of reaction plateaus as substrate concentration in a limiting factor - all substrates are in use
Describe and explain the effect of substrate concentration on the rate of enzyme-controlled reactions
● As substrate conc. increases, rate of reaction increases
○ Substrate conc. = limiting factor (too few enzyme
molecules to occupy all active sites)
○ More Enzyme-substrate complexes form
● At a certain point, rate of reaction stops increasing / levels off
○ Enzyme conc. = limiting factor
○ As all active sites saturated / occupied (at a given time)