Amino Acids and Properties

9 Non-Polar Amino Acids

Glycine, Alanine, Proline, Valine, Leucine, Isolecuine, Methionine, Tryptophan, Phenylananine,

7 Polar and Uncharged Amino Acids

Serine, Threonine, Tyrosine, Asparagine, Glutamine, Cysteine, Histidine

2 Positively Charged Amino Acids

Lysine, Arginine

2 Negatively Charged Amino Acids

Aspartate, Glutamate

Glycine - (Gly, G)

Alanine - (Ala, A)

Proline - (Pro, P)

Valine - (Val, V)

Leucine - (Leu, L)

Isoleucine - (Ile, I)

Methionine (Met, M)

Tryptophan - (Trp, W)

Phenylalanine - (Phe, F)

Serine - (Ser, S)

Threonine - (Thr, T)

Tyrosine - (Tyr, Y)

Asparagine - (Asn, N)

Glutamine - (Gln, Q)

Cysteine - (Cys, C)

Histidine - (His, H)

Lysine - (Lys, K)

Arginine - (Arg, R)

Aspartate - (Asp, D)

Glutamate - (Glu, E)

Glycine Properties

• only achiral amino acid

• smallest and most flexible

• often found in turns and loops

Alanine Properties

• small methyl group side chain

• small non-polar surface area means it won’t trap much water

Proline Properties

• R group covalently bonds back to N

• Least flexible

• Kinks/bends chain and is often found in turns and loops

Valine and Leucine are identical except ___

the beta carbon in valine has 2 methyl groups where the gamma carbon in leucine has the 2 methyl groups

Isoleucine is an isomer of leucine and has

1 methyl group on the beta carbo, 1 on gamma

Methionine Properties

• 1 of 2 AA’s with sulfur

• S is within chain and non reactive

Tryptophan Properties

• Widest = W

• Double Ring = W (Double U)

Phenylanine Properties

• Take alanine and replace methyl with phenyl group

Serine Threonine and Tyrosine all have

hydroxyl groups

Asparagine and Glutamine both have ____ groups

carboxamide

Asparagine and Glutamine are identical except

• asparagine has 1 CH2 group and Glutamine has 2

• 1 before 2 N before Q

Cysteine Properties

• 2nd AA with sulfur

• Capable of H bonding

• Capable of ionic interactions if deprotonated

• Can form disulfide bonds

Histidine has a ____ ring

imidazole - accepts and donates protons easily because side chain is near physiological pH

Lysine has a ___ group which makes it ___

amino, positive

Arginine has a ____ group which makes it ___

Guanidinium, positive

Aspartate and Glutamate both have ___ groups which make them ___

carboxyl, negative

Aspartate and Glutamate are identical except

• Aspartate has 1 CH2 and Glutamate has 2

• 1 before 2, D before E