Amino acids

amino acids also behave as____

neurotransmitters and hormones

amino acid hormones are typiclly hydro____

hydrophillic

protein

linear chain of alpha-amino acids

peptide

short chain of aa

what are the aliphatic NON POLAR hydrophobic AA

Leucine

Isoleucine

Valine

Proline

Alanine

Glycine

what are the aromatic AA

Phenalalanine

Tyrosine

Thryptophan

what is the pKa of TYROSINE

10.1

what are the sulfer containing AA

methionine

cystine

which AA can make disulfide bonds

Cystine

when do disulfide bonds form

oxidizing environment (SH → S not S-)

what are the polar AA

Threonine

Serine

what is the pKa of Threonine

13.6

what is the pKa of serine

13.6

what are the amide containing AA

Glutamine

Asparagine

what are the acidic AA

glutamic acid

aspartic acid

when is glutamic acid called glutamte

when H+ lost

what are the basic AA

Lysine

Arginine

Histidine

Lysine pka

10.5

Arginine pka

12.5

Histidine pKa

6

why is histidine weird

it is technically an acid (pKa below 7) but acts as a base

Zwitterion

ion with +/- but no net charge

what happens to acidic AA at pH 7

side chain is anionic and move towards positive elctrode

what happens to basic AA at pH 7

side chain is cationic and move towards negative elctrode

isomer

same molecular formula but different arrangement

enantiomers

non superimposable mirror images

all amino acids in protein are in the ____ configuration

L

which 2 AA have 2 chiral centers

Isoleucine

Threonine

what does the + form of thalidomide do

sedative

what does the - form of thalidomide do

teratogenic (embryo malfunction)

Isoelectric point

pH where net charge is 0

what happens to AA in electric field at pI

it is stationary

electrophoresis

seperates molecules with electric fields

what is the charge of anode / cathode in paper electrophoresis

Cathode -

Anode +

Capillary electrophoresis

electrophoresis in thin silica capillaries

ion exchange chromatography

polystyrene / silica beads with charge to hold functional groups

how are AA removed from ion exchange chromatography

wash with buffers at higher pH, once pI reached it falls off the beads at different times for different AA

does the condensation of AA happen in neutral water? why / why not?

No, OH is bad leaving group

polypeptide

more than 20 AA

protein

1+ polypeptide

what do Enkephalins do?

natural analgesic, bind to receptors to diminish pain