Cell Recognition

Question 1

What specific molecules do cells have on its surface which is part of their identities?

Answer 1

Antigens

Question 2

What do antigens help identify

Answer 2

Pathogens
Cells from other organisms
Abnormal body cells
Toxins

Question 3

What happens if any part of the organism is recognised as foreign

Answer 3

Leads to an immune response and the production of antibodies

Question 4

What are the different blood types

Answer 4

Blood type A
-has anti-b antibodies
-A antigen
Blood type B
-blood cell type B
-antibodies A
-B antigen
Group AB
-no antibodies
-A AND B antigens
Group 0
- A and B antibodies
-no antigens

Question 5

What is antigenic variability

Answer 5

Some pathogens can change their surface antigens as their DNA mutates which changes the tertiary structure of the surface proteins. This could affect the ability of the immune system to recognise and destroy them

Question 6

What is phagocytosis

Answer 6

1. Pathogen releases chemicals which are recognised by phagocytes (white blood cells) and antigens are recognised. It then engulfs this into a vesicle called phagosome
2. A lysosome fuses with the phagosome and releases lysozymes.
3. Lysozymes hydrolyse the pathogen and harmless products from digestion are absorbed by the phagocyte or released by exocytosis
4. Antigens from the pathogen are displayed on the phagocytes cell membrane turning it into an antigen presenting cell
   -the white blood cell (phagocyte) originate and mature in the bone marrow.