5.2 Phagocytosis

Question 1

What are the 2 types of white blood cells?

Answer 1

Phagocytes and lymphocytes

Question 2

What is the difference between phagocytes and lymphocytes ?

Answer 2

Phagocytes: ingest and destroy the pathogen by process of phagocytosis before it can cause harm

Lymphocytes: are involved in the immune system

Question 3

Explain the process of phagocytosis

Answer 3

1. chemicals products of pathogens or dead, damaged and abnormal cells act as attractants, causing phagocytes to move towards the pathogen
2. phagocytes have several receptors on their cell-surface membrane that recognise, and attach to, chemicals on the surface of the pathogen
3. they engulf the pathogen to form a vesicle, known as a phagosome
4. lysosomes move towards the vesicle and fuse with it
5. lysozyme (enzymes) are present within the lysosome and destroy ingested bacteria by hydrolysis of their cell walls.
6. the soluble products from the breakdown of the pathogen are absorbed into the cytoplasm of the phagocyte.