Proteins - Lecture Four

Question 1

Alpha carbon

Answer 1

Centre carbon

Question 2

Where does the chemical personality of an amino acid come from?

Answer 2

Their side chain

Question 3

What side of the amino acid is protonated?

Answer 3

Amino acid side

Question 4

What side of the amino acid is deprotonated?

Answer 4

Carboxyl side

Question 5

How many different amino acids?

Answer 5

20

Question 6

Glycine, G

Answer 6

Non-chiral and flexible

Question 7

Explain E6V

Answer 7

The first letter is the native amino acid, the number is the location of the mutation and the second letter is the mutated residue

Question 8

Ionisable groups

Answer 8

Some amino acids have ionisable groups which can be classified by their pKa value

Question 9

pKa value

Answer 9

pH at which the group is 50% ionised

Question 10

pI (isoelectric point)

Answer 10

pH at which the net charge on an amino acid (or protein) is zero

Question 11

When amino acids are modified after they are added to a protein?

Answer 11

Post-translational modification e.g. two cysteine bonding together to form a disulphide bond

Question 12

Phosphorylation

Answer 12

Controls enzyme activity

Question 13

Hydroxylation

Answer 13

Prevents connective tissue diseases and scurvy

Question 14

Carboxylation

Answer 14

Needed for blood clotting

Question 15

Short stretch of amino acids joined together by peptide bonds

Answer 15

Peptide

Question 16

Long chain of amino acids joined together by peptide bonds

Answer 16

Protein

Question 17

Amino acid residues

Answer 17

When amino acids body together