Alanine (ala)
nonpolar
aliphatic
Glycine (gly)
nonpolar
aliphatic
Valine (val)
nonpolar
aliphatic
branched chain
Leucine (leu)
nonpolar
aliphatic
branched chain
Isoleucine (ile)
nonpolar
aliphatic
branched chain
Proline (pro)
nonpolar
aliphatic
ring structure that is not aromatic
Phenylalanine (phe)
nonpolar
aromatic
permits absorption of UV light at 280 nm
Tyrosine (tyr)
polar and nonpolar properties
-amphipathic
uncharged
aromatic
OH group
Tryptophan (trp)
nonpolar
aromatic
permits absorption of UV light at 280 nm
Serine (ser)
polar
uncharged
OH group
, Threonine (thr)
polar
uncharge
OH group
Cysteine (cys)
polar
uncharged
SH group
-groups can become oxidized and form disulfide bonds to each other (S-S)
Asparagine (asn)
polar
uncharged
carboxamide group
Methionine (met)
nonpolar
aliphatic
thioether
Glutamine (gln)
polar
uncharged
carboxamide group
Lysine (lys)
polar
charged
positive
Arginine (arg)
polar
charged
positive
Histidine (his)
polar
charged
positive
pKa 6, close to physiological
can act as acid or base
Aspartic acid (asp)
polar
charged
negative
Glutamic acid (glu)
polar
charged
negative
What makes water essential for life?