Amino Acids

Question 1

What amino acids are non-polar and aliphatic at pH 7?

Answer 1

GAVLIMP

Glycine, Alanine, Valine, Leucine, Isoleucine, Methionine, Proline

Question 2

What amino acids are polar and uncharged at pH 7?

Answer 2

NYCS-QT

Serine (S), Threonine (T), Asparagine (N), Tyrosine* (Y), Glutamine (Q), Cysteine (C)

Question 3

What amino acids are non-polar and aromatic at pH 7?

Answer 3

WFY

Tryptophan (W) , Phenylalanine (F) , Tyrosine* (Y)

*Tyrosine is amphipathic

Aromatic ring structures permit absorption of UV light (280nm)

Question 4

What amino acids are negatively charged at pH 7?

Answer 4

(N)ED

Aspartic acid (D), Glutamic acid (E)

Question 5

What amino acids are positively charged at pH 7?

Answer 5

(P)HRL

Histidine, Arginine (R), Lysine

Question 6

What amino acid has a guanidinidium group on its side chain?

Answer 6

Arginine

(Arg, R)

Question 7

What amino acid has a imidazole group on its side chain?

Answer 7

Histidine

(His, H)

Question 8

What amino acids have an -OH group on its side chain?

Answer 8

Serine, Threonine, Tyrosine

T(OH)YS

(Ser, S), (Thr, T), (Tyr, Y)

Question 9

What amino acid has an -SH group on its side chain?

Answer 9

Cysteine

(Cys, C)

Question 10

What amino acids have a carboxamide group on its side chain?

Answer 10

Asparagine, Glutamine

(Asn, N), (Gln, Q)

Question 11

What amino acids have branched side chains?

Answer 11

Valine, Leucine, Isoleucine

VIL

(Val, V), (Leu, L), (Iso, I)

Question 12

What amino acid has a thioether on its side chain?

Answer 12

Methionine

(Met, M)

Question 13

What amino acid has a ring structure on its side chain, but is not aromatic?

Answer 13

Proline

(Pro, P)

Question 14

What amino acids have a chiral carbon on their side chain?

Answer 14

Threonine, Isoleucine (T, I)

Question 15

Glycine

Answer 15

Gly, G

the simplest amino acid

-H side chain

it is achiral

non-polar, aliphatic

Question 16

Alanine

Answer 16

Ala, A

-CH₃

non-polar, aliphatic

Question 17

Valine

Answer 17

Val, V

-CH(CH₃)₂

non-polar, aliphatic

Question 18

Leucine

Answer 18

Leu, L

-CH₂CH(CH₃)₂

non-polar, aliphatic

Question 19

Isoleucine

Answer 19

Ile, I

-CHCH₃CH₂CH₃

non-polar, aliphatic

Question 20

Methionine

Answer 20

Met, M

-CH₂CH₂SCH₃

non-polar, aliphatic

Question 21

Proline

Answer 21

Pro, P

non-polar, aliphatic

differs from the other 20 amino acids because its side chain is bonded to both the alpha carbon and the nitrogen atom

Question 22

Phenylalanine

Answer 22

Phe, F

non-polar, aromatic

Question 23

Tryptophan

Answer 23

Trp, W

non-polar, aromatic

Question 24

Serine

Answer 24

Ser, S

STAT-GC

-CH₂OH

polar, uncharged

(see p 41 for image)

Question 25

Threonine

Answer 25

Thr, T

STAT-GC

-CHCH₃OH

polar, uncharged

Question 26

Tyrosine

Answer 26

Tyr, Y

TPT, STAT-GC

amphipathic*, aromatic, uncharged

*both polar and nonpolar at different parts of the molecule

Question 27

Cysteine

Answer 27

Cys, C

-CH₂SH

polar, uncharged

Question 28

Asparagine

Answer 28

Asn, N

polar, uncharged

Question 29

Glutamine

Answer 29

Gln, Q

polar, uncharged

Question 30

Lysine

Answer 30

Lys, K

-(CH₂)₄NH₃⁺

positively charged

Question 31

Arginine

Answer 31

Arg, R

positively charged

Question 32

Histidine

Answer 32

His, H

positively charged

Question 33

Aspartate

Answer 33

Asp, D

negatively charged

Question 34

Glutamate

Answer 34

Glu, E

negatively charged