Specific Immune Response: Phagocytosis

Question 1

What is a antigen?

Answer 1

protein on the surface of cells (that can cause an immune response

Question 2

What does an antigen do?

Answer 2

allow the immune system to recognise:

1) pathogens
2) cells from organisms of same species
3) abnormal body cells e.g. tumour
4) toxins

Question 3

What is a pathogen?

Answer 3

an organism that causes disease e.g. bacteria, viruses, fungi, protoctista

cause damage by - destroying host cells and producing toxins

Question 4

What is a neutrophil?

Answer 4

a type of phagocyte (WBC)

Question 5

What are antigen presenting cells?

Answer 5

a WBC that presents a pathogen’s antigen on its surface to activate other WBC’s e.g. neutrophil

Question 6

What are opsonins?

Answer 6

molecules that make it easier for phagocytes to engulf pathogens

Question 7

What happens during phagocytosis?

Answer 7

1) phagocyte binds to the foreign antigen on the pathogen
2) pathogen is engulfed into a phagosome
3) lysosomes fuse with phagosome - release enzymes to hydrolyse pathogen

4) phagocyte presents antigens on its cell membrane - activates T-lymphocytes
product is absorbed e.g. glucose