A1 - phagocytosis

Question 1

Process of phagocytosis

Answer 1

-phagocyte attracted to chemicals secreted by pathogen/damaged body cells
-receptors on phagocytes cell surface membrane recognise and attaches to chemicals on the surface of pathogen
-phagocyte engulfs pathogen to form vesicle (phagosome)
-lysosome move towards phagosome and fuse with it (phagolysosome)
-lysozymes (enzymes) in lysosome hydrolyse pathogen (hydrolysis of their cell wall)
-soluble products from break-down of pathogen absorbed into cytoplasm of phagocyte

Question 2

What do phagocytes do

Answer 2

ingest and destroy pathogen by phagocytosis before it can cause harm

Question 3

What does phagocytosis do

Answer 3

-engulf large particles eg bacteria by cells in vesicles formed from cell-surface membrane

Question 4

Describe role of lysosomes in phagocytosis

Answer 4

-migrate towards phagosome formed by engulfing bacterium
-lysosomes release their lysozymes into phagosome where they hydrolyse the bacterium