Class Four Flashcards
3 basic components of an AA
carboxyl group
amino group
R group
all AAs are chiral except for..
glycine
*alpha carbon is bonded to 2 Hs
what makes each amino acid unique
their variable R group
all animal amino acids are of __ configuration
L
all naturally occurring carbohydrates have __ configuration
D
L and D amino acids are..
enantiomeric stereoisomers
what are enantiomeric stereoisomers
molecules with the same connectivity but different spatial orientation
non superimposable mirror images
simplest/smallest carbohydrate
glyceraldehyde
animal amino acids are derived from..
L-glyceraldehyde
animal carbohydrates are derived from..
D-glyceraldehyde
(+) and (-) describe..
optical activity
is L - or +
-
is D - or +
+
what do R and S describe
actual structure or absolute configuration
what do D and L tell us
tells us the basic precursor of a molecule
four categories of AAs
acidic basic non polar & polar
acidic AAs have..
carboxylic acid functional groups
pka of acidic AAs
4
acidic AAs
aspartic acid: asp (D)
glutamic acid: glu (E)
basic AAs
lysine
arginine
histidine
lysine
lys: K
basic AA
pka = 10
arginine
arg: R
basic AA
pka = 12
histidine
his: H
basic (but can act as an acid as well)
pka = 6.5
nonpolar AAs (7)
glycine
alanine
valine
leucine
isoleucine
phenylalanine
tryptophan
glycine
non polar
gly: G
glycine
non polar
gly: G
alanine
non polar
ala: A
valine
non polar
val: V
leucine
leu: L
non polar
isoleucine
ile: I
non polar
phenylalanine
phe: F
non polar
tryptophan
trp: W
non polar
aromatic AAs (3)
phenylalanine
tryptophan
tyrosine
serine
ser: S
polar
threonine
thr: T
polar
tyrosine
tyr: Y
polar