Friday 17th October

Amino Acids

R- group changes to make all the different amino acids

carboxyl group makes it acidic

amine group is the base and it accpets H+ ions

amphoteric - has both acidic and basic properties

they act as pH buffers, they regulate the pH by changing their charge

isoelectric point - ph at which the charge on amino acids is neutral

R-group determines the properties

1.2nd amino group (positively charged, basic)

2. 2nd carboxyl group (negatively charged, acidic)

3. simple hydrocarbon chain (hydrophobic, non-polar)

4. polar hydrocarbon chain (hydorphylic)

protein is determined by the 3D shape

joined together by peptide bonds - requires an enzyme and energy

ionic bond - between charged R-groups

disulphide bond - only between the sulphyl groups of 2 cysteine amino acids

hydrogen bond

Protein Structure

1.Primary (peptide bonds)

2.Secondary (hydrogen bonds)

3.Tertiary (hydrophylic amino acids, hydrogen/ionic/disulphide bonds)

4.Quaternary

Fibrous protein - long chains, strong

Globular protein - irregular structure