unit 2, antigens and lymphocytes

Question 1

what are antigens?

Answer 1

They are proteins on the surface of all cells, they are chemical markers that trigger an immune response.

Question 2

what is antigen variability?

Answer 2

-dna mutates frequently , if it occurs coding for an antigen then the antigen will change shape
- previous immunity made for this antigen ( from previous infection, natural or artificial witha vaccine) will be lost and no longer effcetive, as memory cells no longer recognise the antigen

Question 3

what do antigens enable the immune system to find?

Answer 3

-pathogens
-cells from other organisms (transplanted organisms)
-cancerous cells
-toxins

Question 4

what is a pathogen?

Answer 4

a micro-organism that causes disease

Question 5

where are lymphocytes made and how do they travel?

Answer 5

-they are made when you are a fetus
-they are made when you are older in the bone marrow, and travel in capillaries and can squeeze through walls into tissues

Question 6

what happens when lymphocyes are made that recognise self cells?

Answer 6

they are destroyed/supresssed

Question 7

how do lymphocytes identify foreign cells?

Answer 7

• each cell has specific shapes/antigens on their surface to idnetify it, which are protiens
• the 3D tertiary shape enables it to be unique and identifable

Question 8

what are the two types of white blood cells?

Answer 8

neutrophils
macrophages

Question 9

what are neutrophils?

Answer 9

they engulf and digest pathogens ( and dead human cells, and debris)

Question 10

what are macrophages?

Answer 10

they can punch holes in the bacteria, which would cause the cytoplasm to burst and they stick proteins to the outside of the bacteria to make them more appealing for the neutrophils to destroy