noteS

• antibiotic

  • chemical substances that damage bacterial cells with little harm to human tissue
• bacteriocidal

  • they kill bacteria cells
• bacteriostatic

  • inhibit bacterial growth processes
• how antibiotics work

  interfere with growth/metabolism of bacteria by:

  • inhibiting enzymes needed to form bonds in cell walls, preventing growth/causing death= cell walls weakened and burst underpressure of water entering cell via osmosis
  • binding to ribosomes- inhibits protein synthesis-no enzyme production= no metabolic processes in bacterial cells
  • preventing bacterial DNA coiling to rings- DNA no longer fits into bacterial cell
• dont damage eukaryotic cells

  • no cell walls
  • different enzymes
  • different ribosomes
• dont damage viruses

  • no cellular structures eg ribosomes or cells walls or enzymes