O- Enzymes + DNA =)

Question 1

State the meaning of the term complementary when it is used to refer to DNA strands. (1)

Answer 1

base seq that match A-T & C-G

Question 2

A student hydrolyses a sample of protein to break it down into its constituent amino acids.
State a reagent and the conditions needed for the hydrolysis. (2)

Answer 2

• aq. HCl
• reflux

Question 3

Suggest a suitable reagent for the hydrolysis of a protein. (1)

Answer 3

conc. HCl

Question 4

Cisplatin, [Pt(NH3)2Cl2], is used as an anti-cancer drug.
Cisplatin works by causing the death of rapidly dividing cells.
Name the process that is prevented by cisplatin during cell division. (1)

Answer 4

DNA replication

Question 5

Explain why disuphide bridges between amino acid R groups are stronger than hydrogen bonds. (1)

Answer 5

disulphide bridges = covalent bonds

Question 6

An adverse effect of cisplatin is that it also prevents normal healthy cells from replicating.
Suggest one way in which cisplatin can be administered so that this side effect is minimised. (1)

Answer 6

• Use in very small amounts /
• target the application to the tumour