Treating infections

Question 1

What are antibiotics?

Answer 1

medicines that kill bacteria inside the body

specific bacteria are only killed by a certain antibiotic, so the correct antibiotic must be used

deaths from bacterial diseases have greatly decreased where antibiotics are used

Question 2

What can antibiotics be used for?

Answer 2

treating bacterial infections

Question 3

Give an example of an antibiotic

Answer 3

Penicillin, ampicillin

Question 4

When testing the effects of antibiotics on bacteria in a petri dish, how do you calculate the cross-sectional area of the clear zone?

Answer 4

measure from the widest point

use πr²

this allows you to compare the effectiveness of antibiotics

Question 5

Describe how antibiotics kill bacteria

Answer 5

Antibiotics inhibit cell processes in the bacterium but not the host organism

For example, some antibiotics stop bacterial cell walls forming properly

This does not harm the host animal because animal cells do not have cell walls

Question 6

Some antibiotics work by binding to bacterial ribosomes so that proteins cannot be made.

Bacterial ribosomes are smaller than human ribosomes and have a different structure.

Explain why these antibiotics do not harm human cells.

Answer 6

antibiotics cannot bind to human ribosomes

/too big/cannot fit

Question 7

Explain why doctors do not prescribe antibiotics if the patient has the flu virus

Answer 7

antibiotics only kill bacteria and do not destroy viruses