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11 Cards in this Set
- Front
- Back
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What were Pasteur's experiments? What did he discover from them?
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had 2 flasks of boiled broth. He left one sealed up and unsealed the other. The unsealed one - broth turns cloudy, sealed one remains transparent. Shows micorbes in air can contaminate solutions BUT air doesn't create microbes and they don't arise spontaneously from broth,
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what colour do gram +ve bacteria go when stained?
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purple
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what colour do gram -ve bacteria go when stained?
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red
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whats the difference in structure between gram +ve and gram -ve?
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gram +ve = thick peptidoglycan, teichoic acid
gram -ve = thin peptidoglycan outer membrane, lipopolysaccharide |
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give 4 reasons why the cell wall of bacteria is important.
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1. protecting the bacteria
2. damaging the host - LPS (endotoxin) interacts with immune system 3. target for antibiotics 4. recognition by host - pathogen associated molecular patterns |
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what are PAMPS?
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pathogen asssociated molecular patterns - bacterial structures that asre recognisd by innate immune system and recognised by host as being foreign
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Give 3 examples of PAMPs
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flagellin of bacterial flagella
peptidoglycan of gram + bacteria lipopolysaccharide of gram-ve bacteria |
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what does TLR-2 recognise?
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+ve peptidoglycan
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what does TLR-4 recognise?
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-ve LPS
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what does TLR-5 recognise?
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flagellin
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How does penicillin work?
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B-lactam ring of penicillin resembles D-ala-D-ala end of peptide to which the transpeptide enzyme binds so the transpeptide enzyme binds to penicillin and breaks bond, the molecule is not split and remains attached to the enzyme so it can no longer function - blocks cell wall growth and leads to bacterial lysis
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