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14 Cards in this Set
- Front
- Back
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Definition of an antibiotic? |
A substance produced by a micro-organism (or a similar substance produced wholly or partly by chemical synthesis) which at low concentrations kills or inhibits the growth of other micro-organisms
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Why are antibiotics said to be systematical? |
They only work inside the body |
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Why should drugs have selective toxicity? |
-Affects only the microbe -Affects the microbe much more than the patient |
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What is a bactericidal (C) drug? |
Kills and/or lyses bacterial cell |
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What is a bacteriostatic (S) drug? |
Inhibits growth of bacteria and is reversible |
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What are the three main targets for antibiotics? |
-Metabolic reactions -cell wall -cell membrane EXTRA NOTE: Metabolic reactions and cell membrane are not selective toxicity because these are present in the host cell as well as the microbe |
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What are the four metabolic reactions antibiotics act upon? |
-Folate metabolism = Sulphonamides (S) -DNA synthesis = Fluoroquinolones (C) -RNA sythesis = Rifampicin (C) -Protein synthesis = Tetracyclines (S) or Chlorampenicol (S) |
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Difference in folate metabolism between bacteria and mammalian cells |
Bacteria synthesise folic acid where as humans obtain folic acids from diet |
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What part of the ribosome unit does tetracycline act upon? |
30s |
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What part of the ribosome unit does tetracycline act upon? |
30s |
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What part of the ribosome unit does chloramphenicol act upon? |
50s |
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What part of the ribosome unit does tetracycline act upon? |
30s |
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What part of the ribosome unit does chloramphenicol act upon? |
50s |
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What are the five antibiotic resistance mechanisms? |
-exclusion -excretion -alter targets -destroy antibiotic -modify antibiotic |
