5.2 Phagocytosis

Question 1

What is phagocytosis

Answer 1

The cellular process of engulfing solid particles by the cell membrane to form an internal phagosome by phagocytes

Question 2

What is the process of phagocytosis

Answer 2

~ Phagocyte e.g. macrophage recognises foreign antigens on the pathogen and binds to the antigen
~ phagocytes engulf the pathogen by surrounding it with its cell surface membrane / cytoplasm to form a vesicle called the phagosome
~lysosome fuses with the phagosome and release lysozymes into the phagosome which destroy the ingested bacteria ( pathogen) by hydrolysis of their cell walls
~ the phagocytes absorbs the soluble products of the bacterium hydrolysis
~ Phagocyte becomes antigen presenting and stimulates specific immune response

Question 3

What type of lymphocytes are involved in specific immune response

Answer 3

T-LYMPHOCYTES: cell- mediated immunity ( involves body cells ), mature in the thymus gland
B-LYMPHOCYTES: humoral immunity (involves body fluids ) , mature in bone barrow

Question 4

Has does our body recognise our own cells

Answer 4

~each type of our body cells has specific molecules on its surface that identify it, these molecules have specific proteins with a highly specific 3D- tertiary structure which distinguishes one cell from another.
~these molecules also help the immune system to identify pathogens, toxins, abnormal body cells etc