Paper 1 - Treating Infections

Question 1

Describe how antibiotics kill bacteria

Answer 1

Antibiotics Inhibit cell processes in the bactterium but no
host organism. for example, some antibiotics stop bactenial
cell wals forming properly This does not harm the host
animal because animal cells do not have cell walls.

Question 2

How can we measure the effect 9f antibiotics on bacteria ?

Answer 2

The effects of antiseptics antibiotics ir plant extracts on the growth of bacteria can be studied on a bacterial culture in a petri dish.

Question 3

How to calculate cross sectional area to compare the effects of antibiotics

Answer 3

Comparing the
ls effects of antibiotics

You can calculate the cross- sectional area
of the clear zone using the formula pie(r squared)
(where r= the radius of the circle of the
clear zone). This allows you to compare
how effective different antibiotics are. So

if, in the example on the left, r= 8mm for
antibiotic A and 14 mm for antibiotic B,
then

Area for antibiotic A =T x8 201 mm
Area for antibiotic B Tx 142- 615mm
Antibiotic B is the more effective antibiotc
for this bacterial culture.