M2 C3 Biological molecules Flashcards
what are the 4 most abundant elements present in biological molecules and how many bonds can they have
hydrogen- 1 oxygen- 2 nitrogen- 3 carbon- 4
name 5 important properties of water and relate them to its structure
adhesion- the attraction between water molecules & surface molecules
cohesion- the attraction between water molecules caused by hydrogen bonds, leads to surface tension
good solvent- dissolves most substance
coolant- high specific heat capacity & latent heat
explain what a monomer is
a single unit
how do monomers form polymers
create glycosidic bonds and lose water (condensation reaction) with other monomers
what is a monosaccharide
a single unit of sugar
what is a disaccharide
two sugar units joined to
what is a polysaccharide
many sugars joined together
how are bonds formed in carbohydrates
condensation reactions
describe the structure of starch and how relates to its function
its made from
- amylose: made from 1,4 glycocidic bonds and forms a single coilled strand of alpha glucose which is easily broken down to use for energy
- amylopectin: made from 1,4 and 1,6 glycocidic bonds .: branched. insoluble so it doesnt effect water potential amd is good for storage as it is compact due to the branches
describe the structure of glycogen and how relates to its function
very branched due to 1,4 and 1,6 glycocidic bond
describe the structure of cellulose and how relates to its function
straight due to 1,4 glycosidic bonds and alternating beta glucose molecules, for structural purpose in plant cells
how is a calibration curve used to find unknown concentrations
Where it crosses the x axis
what are the main principals of colorimetry
pfegbthy
describe the structure of triglycerides
- made up of one glycerol and 3 fatty acids
- glycerol is an alcohol and has 3 carbons & 3 -OH groups
- fatty acids have a carboxyl group (-COOH) on one end, attached to a hydrocarbon tail
- fatty acids are acids as they ionise to form H+ and -COO~
describe the structure of phospholipids
same as triglycerides but one of the fatty acids is replaced by a phosphate group
name and describe the bond in lipids
ester
what is the difference between saturated and unsaturated fats
Saturated- single bonds, solid
Unsaturated- double bonds, liquid
test for proteins
Add beiurets solution
test for lipids
Emulsification, and water and mix should become cloudy
test for reducing sugars
benedicts solution and heat,
test for non-reducing sugars
Add benedicts solution should be negative result then add HCL and heat (hydrolysis) then neutralise the acid with NaOH before adding benedicts solution
test for starch
Iodine
principals of chromatography
phrybgs
Rf values
psbrg
Primary structure of proteins & amino acids
Primary
- sequence of amino acids
- peptide bonds
what is the difference between globular and fibrous proteins
Fibrous proteins are relatively long, thin and insoluble in water whereas globular proteins are relatively spherical and soluble in water
name 4 important ions and their role in living organisms
Ca: muscle contractions
Na & K: nerve impulse transmission
K: open stomata
secondary structure of proteins & amino acids
- forms a helix shape or beta sheet chains that lie parallel to each other are joined by H bonds
- bonds involved: peptide, hydrogen, alpha hydrogen bonds between O & H
tertiary structure of proteins & amino acids
This is the folding of the protein into its shape. Coiling & folding brings R groups close to one another
H/ionic/disulphide bridges bonds between R groups hold twists/loops in place
quaternary structure of proteins & amino acids
- association of two or more individual proteins
- R group interactions between submits
- hydrophobic and hydrophilic interactions
Similarities between fibrous and globular
They are all polypeptides encoded by DNA
consist of any combination of the 20 amino acids
ROLES OF LIPIDS
TRIGLYCERIDES
Long term energy store
They are insoluble in water :. can be stored w/o affecting the wa
describe the structure and properties of triglycerides
jfjf
how are phospholipids formed
- condensation reaction between an OH group on a phosphoric acid molecule and one of the three -OH groups on the glycerol forms an ester bond
describe the structure and properties of phospholipids
dds
