amino acids Flashcards
what is alpha carbon
chiral carbon, has 4 different substituents, non symmetrical
how to differentiate between L and D enantiomers
L rotates plane polarised light anticlockwise and D clockwise
how to group amino acids
by side chains
non polar- aliphatic, aromatic, unique
polar- neutral, acidic, basic
how is hydrophobic character calculated
hydrophobic character= log Pow (amino acid)-log Pow (glycine)
what is Pow
Pow=partition coefficient in n-octanol water
what is a zwitterion
molecule with 2 or more functional groups that has both positive and negative electrical charge
what is pI
pI=isoelectric point=pH which molecule is neutral
what is the importance of pi
tells us how molecule will solubilise in water
henderson hasselbalch equation
pKa=pH+log10[HA]/[A-]
what are the consequences of modifying amino acid side chains chemically
changes 3D structure of protein which means the function also changes
example of chemical modification of amino acid side chain
phosphorylation of serine, transfer of phosphate group, regulates protein function and transmits signals through cell
