Amino acid structures

Question 1

Describe the structure and any main features of alanine

Answer 1

1. Ala (A)
2. Methyl group attached to central carbon
3. Hydrophobic- found on inside of protein structure

Question 2

Describe the structure and any main features of valine

Answer 2

1. Val (V)
2. CH3CHCH3 group (C2 attached to central carbon)
3. Hydrophobic- found on inside of protein structure

Question 3

Describe the structure and any main features of leucine

Answer 3

1. Leu (L)
2. CH2CH(CH3)CH3 Isobutyl
3. Hydrophobic- found on inside of protein structure

Question 4

Describe the structure and any main features of isoleucine

Answer 4

1. Ile (I)
2. CH(CH3)CH2CH3
3. Hydrophobic- found on inside of protein structure

Question 5

Describe the structure and any main features of Phenylalanine

Answer 5

1. Phe (F)
2. Methylbenzene - CH2 attached to main carbon
3. Hydrophobic- found on inside of protein structure

Question 6

Describe the structure and any main features of Proline

Answer 6

1. Pro (P)
2. CH2CH2CH2 carbon-3 (cyclic structure) joins on to NH2 group of the standard amino acid structure
3. Hydrophobic- found on inside of protein structure

Question 7

Describe the structure and any main features of Methionine

Answer 7

1. Met (M)
2. CH2CH2SCH3
3. Hydrophobic- found on inside of protein structure

Question 8

Describe the structure and any main features of Glycine

Answer 8

1. Gly (G)
2. Hydrogen
3. Hydrophobic- found on inside of protein structure
4. A lot of flexibility because not such a long side chain.

Question 9

Describe the structure and any main features of aspartic acids

Answer 9

1. Asp (D)
2. CH2COOH
3. Charged amino acids- attract to each other to form salt bridges
4. Negatively charged

Question 10

Describe the structure and any main features of Glutamic Acid

Answer 10

1. Glu (E)
2. CH2CH2COOH
3. Charged amino acids- attract to each other to form salt bridges
4. Negatively charged

Question 11

Describe the structure and any main features of Arginine

Answer 11

1. Arg (R)
2. (CH2)3NHC(=NH)NH2
3. Charged amino acids- attract to each other to form salt bridges
4. Positively charged

Question 12

Describe the structure and any main features of Lysine

Answer 12

1. Lys (K)
2. (CH2)4NH2
3. Charged amino acids- attract to each other to form salt bridges
4. Positively charged

Question 13

Describe the structure and any main features of Serine

Answer 13

1. Ser (S)
2. CH2OH
3. Polar amino acid

Question 14

Describe the structure and any main features of Threonine

Answer 14

1. Thr (T)
2. CH(OH)CH3
3. Polar amino acid

Question 15

Describe the structure and any main features of Thryosine

Answer 15

1. Tyr (Y)
2. CH2BenzeneOH
3. Polar amino acid
4. Good absorber of UV- aromatic

Question 16

Describe the structure and any main features of Histadine

Answer 16

1. His (H)
2. CH2(CYCLIC C-NH=CH-NH-CH=)
3. Polar amino acid
4. Used for cloning or purifying proteins as a tag- strong affinity to metals.

Question 17

Describe the structure and any main features of Cysteine

Answer 17

1. Cys ( C)
2. CH2SH
3. Polar amino acid
4. Make proteins stronger- can form covalent di-sulfide bond

Question 18

Describe the structure and any main features of Tryptophan

Answer 18

1. Trp (W)
2. CH2(CYCLIC C=CH-NH-C=C-) Benzene attached to carbon=carbon in cyclic ring.
3. Polar amino acid
4. Aromatic- absorb UV

Question 19

Describe the structure and any main features of Asparagine

Answer 19

1. (Asn (N)
2. CH2C=ONH2
3. Polar amino acid

Question 20

Describe the structure and any main features of Glutamine

Answer 20

1. Gln (Q)
2. CH2CH2C=ONH2
3. Polar amino acid

Question 21

Name the aliphatic amino acids

Answer 21

1. Alanine A
2. Valine V
3. Leucine L
4. Isoleucine I

Question 22

Name the aromatic amino acids and state their properties

Answer 22

1. Phenylalanine F
2. Thyrosine Y
3. Tryptophan W
4. All absorb UV: W is best then Y then F

Question 23

Name four common features of all amino acids

Answer 23

1. Carboxyl group
2. Amino group
3. Side chain (R group)- distinguishing feature
4. H atom