1-amino acids Flashcards
which C is C1
the C=O one
which C is C2
alpha carbon
do all amino acids have beta carbon
all but glycine
which aa have branced beta carbons
valine and isoleucine
which aa have branched gamma (4) carbons
leucine
what is the weight of free aa (average)
128Da
what is the weight of aa residue (average)
110Da
what makes the difference in average weight of free aa and residue
the mass of water from peptide bond formation
how many H bonds can histidine donate
2 when protonated
how many H bonds can histidine accept
none when protonated
1 if non protonated
how many H bonds can amides donate
2 (from NH2)
how many H bonds can amides accept
2 (2 lone pairs on C=)
how many H bonds can arginine donate (just the R group)
5
rate
Phe, Tyr, His, Trp
in order of decreasing polarity
His, tyr, Trp, Phe
where do tyrosine and tryptophan absorb strongly in ultraviolet
280nm