3. Anaerobiosis Flashcards
What does superoxidase dismutase do?
detoxifies oxygen radicals
What does catalase do?
decomposes H2O2
How do aerotolerant bacteria, which lack catalase, deal with H2O2?
have peroxidase enzymes which derive electrons from NADH2 to reduce peroxide to H2O
How are photosynthetic organisms protected from oxygen radicals?
carotenoid pigments which react with the radicals
How to Clostridium spp. obtain oxygen?
substrate level phosphorylation
What are the 7 clostridium botulinum toxin types?
A B C1 D E F G
Which toxin types are most protein for humans?
A B E F
How does botulinum toxin cause death?
blocks Act release which leads to paralysis - respiratory failure
What does the LC of botulinum toxin do once cleaved?
It cleaves SNAP, VAMP and syntaxin
What does the tetanus exotoxin do?
fixes to gangliosides, blocking the release of glycine and GABA neurotransmitters
How does the LC of the tetanus exotoxin work and what kind of enzyme is it?
It cleaves synaptobrevin 2 so vesicles containing the neurotransmitter cannot bind
It is a zinc metalloprotease
What are the names of the C. difficile toxins?
Toxin A and B
What do the C difficile toxins do?
glucosylate the host cell G proteins
