B: Mary

Question 1

Why is it more important to have proofreading in DNA replication than RNA synthesis?

Answer 1

DNA is being replicated to form 2 new cells with same information as mother cell: if there’s an error, the 2 new cells will inherit it, and so on to future generations
If there’s an error in RNA synthesis, it will just to stay in that amino acid/protein: this error will only last for the length of the cell’s life and won’t be passed on to future gens

Question 2

What makes proline unusual?

Answer 2

Proline is an imino acid- it has an imino (H2N+) instead of an amino (H3N+) group. It also has a ring structure which makes it rigid and means that structures with it are less flexible (ie collagen). Beta turns happen at prolines

Question 3

Aromatic group

Answer 3

Have a carbon ring structure / relatively non-polar and so hydrophobic / tyrosine Y and trytophan W can absorb UV light / tyrosine Y (OH group) and tryptophan W (indole ring) are more polar than phenylalanine F