30.5- THE ACTION OF ANTI-CANCER DRUGS

Question 1

What do cancers have in common?

Answer 1

‘rogue’ cells which have lost control over their growth + replication + grow much faster than normal cells

Question 2

What shape does cisplatin have?

Answer 2

square planar

Question 3

How does cisplatin work?

Answer 3

by bonding to strands of DNA, distorting their shape + preventing replication of cells

Question 4

Where does the cisplatin molecule bond?

Answer 4

molecule bonds to nitrogen atoms on two adjacent guanine bases on strand of DNA

Question 5

Why is the cisplatin molecule able to bond to nitrogen atoms on two adjacent guanine bases on a strand of DNA?

Answer 5

nitrogen atoms of guanine molecules have lone pairs of electrons which form dative covalent bonds with platinum
chloride ions in cisplatin displaced by water
water ligands then displaced by nitrogen on guanine as nitrogen is better ligand

Question 6

What is a side effect of cisplatin?

Answer 6

it will bonds to DNA in healthy cells + cancerous ones but cancer cells replicating faster than healthy cells, and so effect on drug greater on cancer cells, than on normal cells
but healthy cells that replicate quickly, i.e. hair follicles, significantly affected