Biological molecules Flashcards
how to test for reducing sugars
add benedicts reagent then heat mixure gently for 5 minutes if turns from blue to orange reducing sugar is present
what is a reducng sugar
it donates electrons in this oinstance to the benedicts reagent causing copper sulfate to turn into red percipitate copper oxide
how to test for non reducing sugar
add hcl and heat for five minutes this will hydrolyse any disacchride then add the sodium hydrogen carbonate and then add benedicts reagent
how to test for starch
add sample to test tube add a few drops of iodine it will turn from orange to blue black
what are the four roles of lipids
for energy store
for insulation
for waterproofing
for protection
why can hydrogen bonds form between peptide bonds
the hydrogen in the the amine group is slightly positive chanrged and the oxygen is slightly negatively charged
how to test for protiens
place a sample in a test tube add sodium hydroxide then add beieuret reagent it will turn purple blue means no prOTien is present
how to test for lipids
take a grease free test tube add some ethanol to the sameple pour into water and shake thoroughly and if white emulsion forms lipid is present
