Biology 6.2 Phagocytosis

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  • Created by: Anna
  • Created on: 30-04-13 23:59

Two types of white blood cell: Phagocytes and lymphocytes.

Barriers to entry

  • Protective covering = skin covers body surface, most pathogens find it hard to penetrate this physical barrier.
  • Epithelia covered in mucus = Mucus produced by epithelial layers is further defence against invasion. In lungs, pathogens stick to this mucus, transported away by cilia, up trachea and swallowed into stomach.
  • Hydrochloric acid in stomach = low pH denatures enzymes of most pathogens, killing the organisms.

Phagocytosis

Large particles are far too big to cross cell-surface membrane by diffusion/active transport.

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