Amino acids! (double sided deck)

Question 1

Valine/ Val

Answer 1

V. Large, non-polar/hydrophobic. Often in cores of water-soluble proteins. Tend to stick together. When exposed, often important in molecular recognition. CH(CH3)2

Question 2

Leucine, leu

Answer 2

L. Large, non-polar/hydrophobic. Often in cores of water-soluble proteins. Tend to stick together. When exposed, often important in molecular recognition. CH2CH(CH3)2.

Question 3

Isoleucine, Ile

Answer 3

I. Large, non-polar/hydrophobic. Often in cores of water-soluble proteins. Tend to stick together. When exposed, often important in molecular recognition. CH(CH3)CH2CH3

Question 4

Phenylalanine, Phe

Answer 4

F. Large, non-polar/hydrophobic. Often in cores of water-soluble proteins. Tend to stick together. When exposed, often important in molecular recognition. CH2Phe

Question 5

Methionine, Met

Answer 5

M. Hydrophobic. CH2CH2SCH3.

Question 6

Cysteine, Cys

Answer 6

C. Hydrophobic. Cys often paired in disulfide bridges (cystine), and while free often involved in metal coordination+ enzyme activity. CH2 SH

Question 7

Alanine, Ala

Answer 7

A. Non-polar, small, often on protein surface. Inert. CH3

Question 8

Glycine, Gly

Answer 8

G. No sidechain/ stereospecificity. Often in tight spots where no room for sidechain. H

Question 9

Serine, Ser

Answer 9

S. OHs normally H bond, often by looping back to backbone, so often buried. Seine nucleophilic, often catalytic. OH can link modifying groups like Pi. CH2OH

Question 10

Threonine, Thr

Answer 10

T. OHs normally H bond, often by looping back to backbone, so often buried. Seine nucleophilic, often catalytic. OH can link modifying groups like Pi. CHOHCH3

Question 11

Tyrosine Tyr

Answer 11

Y. Bulky (6 ring and 6 ring+ 4C/1N ring respectively). Largely non-polar. H bonding functionalities so can appear on protein surfaces. CH2PheOH

Question 12

Tryptophan, Trp

Answer 12

W. Bulky (6 ring and 6 ring+ 4C/1N ring respectively). Largely non-polar. H bonding functionalities so can appear on protein surfaces.CH2+5-ring with N, joined to 6-ring (aromatic)

Question 13

Proline, Pro

Answer 13

P. Sidechain cyclised to main chain, so backbone N has 1 H instead of 2 (when not polymerised). Unique geometric properties, usually kinks alpha helices, often found in tight turns.

Question 14

Histidine, His

Answer 14

H. Ring can be protonated. pK~6, varied w/ env. +ve @ low pH. Reversible protonation-> catalysis. CH2+ 5-ring with 2 Ns, aromatic

Question 15

Asparagine, Asn

Answer 15

N. Neutral, v. polar/hydrophilic. Usually on protein surfaces. Asn can be glycosylated. CH2CONH2

Question 16

Glutamine, Gln

Answer 16

Q. Neutral, v. polar/hydrophilic. Usually on protein surfaces. CH2CH2CONH2

Question 17

Aspartate, Asp

Answer 17

D. -ve @ pH7, often on surface+ involved in catalysis. If buried, must be paired w/+ve residue to form salt-bridge. CH2COOH

Question 18

Glutamate, Glu

Answer 18

E. -ve @ pH7, often on surface+ involved in catalysis. If buried, must be paired w/+ve residue to form salt-bridge. CH2CH2COOH

Question 19

Arginine, Arg

Answer 19

R. +ve @ pH7, occasionally involved in catalysis. (CH2)3NH2CNHNH2.

Question 20

Lysine, Lys

Answer 20

K. +ve @ pH7, occasionally involved in catalysis. (CH2)4NH2