biological molecules-unit 2 Flashcards
what is a condensation reaction?
a reaction that forms a bond between two molecules however it removes a molecule of water
what is a polymer
a large long chain molecule comprised of many monomers joined together
what is a hydrolysis reaction?
a chemical reaction that breaks a bond between two molecules by the addition of water
what is the bond between two monosaccharides?
a glycosidic bond
what are monomers of the disaccharide maltose
alpha glucose
what is the test for sugars
add benedict’s reagent to sample and heat it will go red/orange/green if reducing sugar is present will remain blue if it is not present
what is the test for starch?
add iodine to the sample if starch is present sample changes from a brown-orange colour to dark blue starch is present
what is the test for lipids
dissolve sample with ethanol and shake then add to water if a white emulsion forms, a milky white emulsion will form
what is the test for proteins?
add a few drops of sodium hydroxide solution
then add copper(II) sulfate solution
it will go purple if protein is present
what is a peptide bond?
the bond between two amino acids
what is the primary structure of a protein
the sequence of amino acids
what is the secondary structure of a protein
the formation of alpha helicies and beta pleated sheets
what is the teritary structure of a protien
the 3D folding into shape held together by various bonds e.g hydrogen bonds, disulfide bridges, covalent bons
what is the quaternary structure of a protien
the addition of additional polypeptide chains or a prosthetic group
what is the bond in a lipid
ester bond
why aren’t lipids polymers
as they are not made from monomers
name three roles of lipids
- waterproofing
- insulation
- source of energy
name three characters of lipids
- the proportion of oxygen to carbon and hydrogen is smaller than in carbohydrates
-they are insoluble in water
they are soluble in organic solvents such as alcohols and acetone
what is an unstaurated lipid
a lipid that contains a carbon carbon double bond
what is a saturated lipid
a lipid that does not contain a carbon carbon double bond
how is starch adapted to it’s function? (4)
- it is insoluble so it is osmotically inactive
- it is compact so alot can be stored in small spaces
- it’s highly branched so it can be hydrolysed quickly to release glucose
- it is large so it won’t diffuse in and out of the cell
how is glycogen adapted to it’s function?
compact
osmotically inactive
very highly branched so it can be hydrolysed extremely quickly to release glucose when nessacary
how is cellulose adapted to it’s function?
it is long straight chains that form microfibrils
it is insoluble
it has hydrogen bonds between chains that provides tensile strength
what are the monomers of lactose
lactose and glucose
what are the monomers of sucrose
glucose and fructose
what are the monomers of maltose
glucose and glucose
name two features of a globular protein
soluble
hydrophillic
name two features of a fibrous protein
insoluble
provide strength
