Effect bacteria in different ways (prevent protein synthesis, prevent DNA synthesis etc)
May effect cell wall - cell wall allows bacterial cell to take up water by osmosis without bursting (osmotic lysis) - e.g. inhibit cross linkages within cell wall structure. This weakens the cell wall and causes the cell to burst by osmotolysis.
Only effect cell wall when bacterial cell is growing
e.g. penicillin
Some bacteria may become resistant to antibiotics - pump antibiotic out of cell, change target protein for antibiotic within cell, destroy antibiotic when it enters the cell
Resistant forms survive when treated with antibiotic and continue to reproduce - survival of the fittest
Important examples for AQA - Tuberculosis and MRSA
Tuberculosis - long treatment (6 months) so when patients start to feel better they stop taking antibiotic. Not all bacteria have been destroyed - most resistant forms to antibiotic survive. These survive, reproduce - lead to antibiotic resistant strains
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