Extra content for essays - Botulism

Question 1

What do they do?

Answer 1

Inhibit the release of acetylcholine and therefore reduce muscle contraction

Question 2

How many serotypes does C.botulinum have?

Answer 2

8

Question 3

What are the 2 chains called?

Answer 3

Heavy and light

Question 4

What does the heavy chain do?

Answer 4

Binds to complementary receptors on the pre synaptic membrane forming a toxin receptor complex which is taken up by the cells via endocytosis

Question 5

What does the light chain do?

Answer 5

Prevent the fusing of vesicles with the membrane by binding to SNAP25 proteins

Question 6

What is the importance of this?

Answer 6

Prevents ACh from binding to post synaptic receptors so decreased depolarisation and no action potentials reaching the muscle so no Ca2+ ions released so no muscle contraction leading to muscle paralysis