A-level Chemistry/OCR (Salters)/Amino acids
α-Amino acids[edit]
The general structure of an α-amino acid. The α-carbon is displayed in orange, and the side chain is denoted by R. This style of diagram does not indicate whether the amino acid is an L or a D enantiomer.
The stereochemistry of an L-amino acid. All amino acids in nature are L-amino acids, except for bacterial cell walls and the odd w:en:cone snail or two.
A skeletal formula of a general α-amino acid. The α-carbon is displayed as an orange circle
The skeletal formula of a general L-α-amino acid, the enantiomeric form found in nature.
The skeletal formula of a general D-α-amino acid, the enantiomeric form not found in nature. D-amino acids can be synthesised artificially in a laboratory.
The twenty protein-forming amino acids[edit]
glycine
Gly, G
L-alanine
Ala, A
L-valine
Val, V
L-leucine
Leu, L
L-isoleucine
Ile, I
L-phenylalanine
Phe, F
L-proline
Pro, P
L-tryptophan
Trp, W
L-serine
Ser, S
L-threonine
Thr, T
L-cysteine
Cys, C
L-methionine
Met, M
L-aspartic acid
Asp, D
L-glutamic acid
Glu, E
L-asparagine
Asn, N
L-glutamine
Gln, Q
L-tyrosine
Tyr, Y
L-histidine
His, H
L-lysine
Lys, K
L-arginine
Arg, R
Reactions of amino acids[edit]
Amino acids can undergo condensation reactions, forming polypeptides.