BB1 Amino Acids

Question 0

Usually amino acids exist as a dipolar ion, known as a

Answer 0

Zwitterions
• pH = 1 positively charged
• pH = 7 dipolar ion
• pH =11 negatively charged

Question 1

Five elements in amino acids

Answer 1

• Hydrogen
• Carbon
• Nitrogen
• Oxygen
• Sulphur

Question 2

Isomer of amino acids found in proteins

Answer 2

L-isomer

Question 3

Key features of the different side chains

Answer 3

• size
• shape
• charge
• hydrophobic character
• hydrogen bonding capacity
• chemical reactivity

Question 4

Aliphatic amino acids

Answer 4

• Glycine to Methionine

* Increasing in size, hydrophobicity

Question 5

Aliphatic amino acid with sulphur

Answer 5

Methionine

Question 6

Aliphatic amino acid with a cyclic side chain and found in bends

Answer 6

Proline

Question 7

Aromatic Amino acids

Answer 7

• contain a phenyl ring

* hydrophobic

Question 8

Less hydrophobic aromatic amino acid due to presence of OH group

Answer 8

Tyrosine

Question 9

Aromatic amino acid, widest

Answer 9

tryptophan (W)

Question 10

Highly reactive amino acid, has SH group and contains sulphur

Answer 10

Cysteine

Question 11

OH groups makes an amino acid

Answer 11

More hydrophilic (water loving, on surface)

Question 12

Histidine

Answer 12

• basic amino acid
• charge on side chain varies with pH
• enzyme function

Question 13

Aspartic and Glutamic Acid

Answer 13

• AKA Aspartate and Glutamate
• acidic amino acids
• negatively charged at physiological pH

Question 14

Asparagine and Glutamine

Answer 14

• uncharged derivatives of Aspartate and Glutamate

* NH2 replaces side chain oxygen in carboxylate group

Question 15

Degenerate property of codon

Answer 15

replace base in 3rd position gives same amino acid = lower chance of mutation
doesn’t work for 2nd position

Question 16

Lysine & arginine

Answer 16

• basic amino acids
• positive group at pH 7
• longest side chains