6.3 Action of antibiotics

Question 1

What are antibiotics?

Answer 1

Chemicals that stop bacterial cells from growing

Question 2

How do antibiotics not damage the mammalian cells?

Answer 2

By targeting the differences in structure or biochemistry between bacterial and mammalial cells

Question 3

Give an example of a bactericidal antibiotic

Answer 3

Penicillin

Question 4

How do bactericidal antibiotics work (with an example)?

Answer 4

Kill bacteria by interfering with an aspect of bacterial structure or biochemistry in a way that causes it to die
Penicillin acts on bacterial cell walls, breaking them open as they try to grow

Question 5

Give an example of a bacteriostatic antibiotic

Answer 5

Tetracycline

Question 6

How do bacteriostatic antibiotics work (with an example)?

Answer 6

Prevent the growth and reproduction of bacteria
Giving the immune system time to deal with the infection and destroy the infectoin
Tetracycline interferes with protein synthesis in the ribosomes in bacteria

Question 7

Why can’t bactericidal antibiotics be used long term in the gut?

Answer 7

Many of the bacteria in the gut are beneficial
Long term use would kill them
Therefore bacteriostatic antibiotics would be better to use as these populations will have the chance to recover once it is removed

Question 8

TRUE/FALSE: A single antibiotic can be both bacteriostatic and bactericidal

Answer 8

True, depending on the concentration