carbs and lipids Flashcards
eg of monomers
monosaccharides, amino acids, nucleotides
egs of polymers
polysaccharides, polypeptide, polynucleotide
bond for each 3 monomers m,aa,n
glycosodic, peptide, phosphodiester
eg of polysaccharides
starch, glycogen, cellulose
egs of amino acids
enzymes, haemoglobin
egs of polynucleotides
dna, rna
alpha glucose structure
beta glucose structure
glucose + glucose
maltose
galactose + glucose
lactose
glucose + fructose
sucrose
bonds of amylopeptin (starch)
carbon 1-4 glycosidic bonds which make it compact - helical structure
amylose - bonds (starch)
branched chains - carbon 1-6 and 1-4 glycosidic bonds which gives a large surface area for rapid hydrolisis by enzymes to release glucose for respiration
advantages of starch structure
insoluble so doesnt affect water potential
large so doesn’t diffuse out of cells
coils into compact shape
advantages of structure for glycogen
more higly branched
and short chains
and larger surface area
lead to glycogen being more rapidly hydrolysed into glucose used in respiration
what is made up of alpha glucose?
starch (plants) and glycogen (animals)
what is made up of beta glucose?
cellulose - what plant cell walls are made from
structure of cellulose
long straight unbranched chains joined together in layers by weak hydrogen bonds to form microfilbrils
advantages of cellulose structure
weak h bonds provide strength as they are large in numbers
what are egs of reducing sugars
glucose galactose maltose fructose lactose
what are egs of non reducing sugars
sucrose
benedicts test for reducing sugars
add 2cm3 benedicts solution to a sample, heat to 95C
a coloured change from blue to red precipitate visible
benedicts test for non reducing sugars
if no change in benedicts test for reducing sugar
head a sample with acid and heat to 95C
then neutralise with alkali
add 2cm3 benedicts solution
heat to 95C
red precipitate
how you would produce a calibration curve for a reducing sugar of unknown concentration and abtain results
make up several random known conc of a reducing sugar (glucose, eg)
carry our benedicts test on each sample
use a colorimeter to measure absorbance reading (au)
plot a calibration curve
find the conc of unknown sample using calibration curve
test for starch
add 2 drops of KI solution to sample
black colour indicates starch presence
fucntions of lipids
conduct heat slowly, good thermal insulator
stored around delicate organs to protect
triglyceride strcutre
made from one molecule of glycerol to three fatty acids joined by ester bonds
why are triglycerides not a polymer
not made up of the same/similar monomers
unsaturated fatty acid vs saturated fatty acid structure difference
saturated - no double bonds between carbon atoms (solid at room temp as its straight and closely packed)
unsaturated - double bond between at least one carbon atom so has a kink, leading to being liquid at room temp
advantages in triglyceride structure
low mass to energy ratio so makes them a good source of energy
they dont affect water potential of a cell as they are insoluble in water
high hydrogen to oxygen ratio so they are a good source of water when broken down
emulsion test for lipids
crush sample
sample added to 2cm3 of ethanol
shake
add a few drops of water
shake
white emulsion layer forms
phospholipid structure
one glycerol 2 fatty acids one phosphate group
charge of phosphate group vs fatty acid tails
phosphate group - negative cahrge (polar)
fatty acid tails - no cahrge (non-polar)
phospho-glycerol head vs fatty acid tails attraction to water
phospho-glycerol head hydrophillic
fatty acid tails hydrophobic
allows the phospholipids to form a bilayer in water, forming the basis of the cell membrane
