Amino Acids Flashcards
Glycine
Nonpolar
Gly, G
The only achiral amino acid
Alanine
Nonpolar
Ala, A
–Can be converted to pyruvate through transamination and thus is very important in metabolic functions. It is the link between glycolysis, gluconeogenesis, and the citric acid cycle
Valine
Nonpolar
Val, V
Leucine
Nonpolar
Leu, L
–isobutyl side chain
Isoleucine
Nonpolar
Ile, I
–Remember “Iso”leucine is a constitutional isomer of leucine
–secbutyl substituent
Methionine
Nonpolar
Met, M
–One of 2 amino acids that has sulfur in it
–Used as a start codon when translating from mRNA into a protein
Phenylalanine
Nonpolar
Phe, F
–Aromatic
Tryptophan
Nonpolar
Trp, W
–The only amino acid with a dicyclo R group (most complicated R group)
–This is nonpolar because the electrons on nitrogen are used for aromaticity.
Proline
Nonpolar
Pro, P
–R group swings back around to attach to the parent, just as the loop on the letter “P” swings back around to attack to the backbone on the letter
–the R group causes Proline to kink a chain - this is why proline is found at sharp turns in protein structures
Serine
Polar neutral
Ser, S
–Any amino acids with an OH group in side chain are good for hydrogen bonding and phosphorylation (b/c the Hydrogen can be removed and a phosphate can bond to the oxygen.)
Threonine
Polar neutral
Thr, T
–chiral carbon in the side chain
Cysteine
Polar Neutral
Cys, C
Tyrosine
Polar neutral
Tyr, Y
–“Tye”rosine like a “tire” in the middle
Asparagine
Polar Neutral
Asn, N
–Not basic despite the NH2 b/c NH2 is part of an amide instead of an amine, and amides are much less basic than amines
Glutamine
Polar neutral
Gln, Q
–Glutamine is a “glutton” (gln) compared to asparagine b/c it ate an extra CH2
–glutamine is not basic despite the NH2 group b/c it’s an AMIDE which is way less basic than an amine
Aspartate
Polar Acidic
“Aspartic Acid” when protonated
Asp, D
Glutamate
Polar Acidic
“Glutamic Acid” when protonated
Glu, E
Lysine
Polar Basic
Lys, K
–“L” is taken for the one letter abbreviation, “oK, we’ll take K.”
Arginine
Polar Basic
Arg, R
Histidine
Polar Basic
His, H
–Memorize the pKa for the side chain. pKa=6, which is very close to physiologic pH, which means histidine is easily protonated and deprotonated. This has implications for structure changes and therefore function changes.
