amino acids can be hydrophobic, hydrophilic, or charged (3 groups)
Hydrophobic groups (nonpolar):
glycine(gly, G), Alanine (Ala, A), Valine (Val,V), Leucine (Leu,L), Isoleucine (Ile,I), Methionine (Met, M), Phenylalanine (Phe, F), Tryptophan (Trp, W), Proline(Pro,P)
Proline: side chain is connected to the main chain
Hydrophilic (polar)
Serine(Ser, S), Threonine (Thr, T), Cysteine(Cys, C), Tyrosine(Tyr, Y), Asparagine(Asn, N), Glutamine(Gln, Q)
Charged
acidic negatively charged (very polar) (negative oxygen at the end)
aspartic acid (asp, D), Glutamic acid(Glu, E)
basic positively charged (amino groups at the end)
Lysine(lys,K), Arginine(Arg, R), Histidine(His, H)
Glycine is most flexible amino acid because it has smallest side chain and can move rotate and bend easier
Aliphatic side chains: alanine, valine, isoleucine, leucine
Hydroxyl containing side chains: serine, threonine
negatively charged acidic residues: aspartate, glutamate
basic side chains: lysine, arginine (NOT HISTIDINE bc at pH 7, 90% not charged)
amid-containing residues: asparagine, glutamine
proline: cyclic ring imposes constraints on N-Ca bond
Histidine: partially charged around pH7
aromatic residues: phenylalanine, tyrosine, tryptophan
Sulphur containing residues: cysteine and methionine
cysteine may get close to another cysteine and form a covalent bond (only amino acid whose side chain can form covalent bond ie. disulfide bond) which makes it more durable
acts as antibody
antibodies always have heavy chain with 2 disulfide bonds and is very sturdy and light chain connected by disulfide bond
heavy chain is in all antibodies
ALL AMINO ACIDS
Alanine(A, Ala): nonpolar, small sidechain, unreactive
Arginine (R, Arg): positively charged, ionic interactions with negatively charges, contains acid
Asparagine(N, Asn): polar, uncharged, can form hydrogen bonds, small, frequently abundant, hydrophilic
Aspartate(D, Asp): negatively charged, interacts with positively charged groups
Cysteine(C, Cys): contains SH group (sulfur), very reactive, polar, can form polar bond with other cysteine, hydrophilic
Glutamine(Q, Gln): polar, uncharged, hydrogen bond, hydrophilic, contains acid
Glutamate(E, Glu): negatively charged, commonly replaces aspartate (acid)
Glycine(G, Gly): uncharged, smallest, very replaceable, hydrophobic, nonpolar
Histidine(H, His): contains C3N2H4 ring, positively charged (partially), basic, pH around 7
Isoleucine(I, Ile): hydrophobic, non polar, unreactive, aliphatic, commonly replaces valine
Leucine(L, Leu): hydrophobic, nonpolar, aliphatic
Lysine(K, Lys): positively charged, ionic interactions, basic
Methionine(M, Met): contains Sulfur, unreactive, nonpolar, hydrophobic
Phenylalanine(F, Phe): hydrophobic, aromatic, unreactive, nonpolar
Proline(P, Pro): cyclic ring, hydrophobic, nonpolar
Serine(S, Ser), polar, uncharged, contains -OH hydroxyl group, hydrogen bonds, hydrophilic, commonly replaces alanine and threonine
Threonine(T, Thr): polar, uncharged, contains -OH hydroxyl group, hydrogen bonds. hydrophilic
Tryptophan(W, Trp): large, hydrophobic, aromatic, reactive w/ nitrogen, nonpolar
Tyrosine(Y, Tyr): aromatic, contains -OH hydroxyl group, ionizes at pH 0, hydrophilic
Valine(V, Val): hydrophobic, aliphatic, nonpolar, hydrophobic
Polar side chains: will have electronegative elements such as O, S, N
Acidic: negatively charged O
Basic: positively charge N