microbiology and pathogens (6)

Question 1

what do lymphocytes do

Answer 1

recognise specific antigens
and can become memory cells

Question 2

what are the types of lymphocytes and what do they differentiate into

Answer 2

B cells -> b memory cells + plasma cells

T cells -> T helper, T killer, T helper memory, T killer memory

Question 3

what do phagocytes do

Answer 3

engulf and digest pathogens/ antigen/ cell debris
then present antigen to T-cell

Question 4

two examples of phagocytes

Answer 4

macrophages
neutrophils

Question 5

outline the process of phagocytosis

Answer 5

1. phagocyte binds to pathogen/ antigen/ cell debris
2. the material is then taken into the phagocyte via endocytosis -> forming a phagosome
3. the phagosome will then fuse with a lysosome containing digestive enzymes -> digesting the material into smaller molecules e.g. antigens/ antigen fragments
4. antigens/ antigen fragments are then presented on their surface for T cells to recognise

Question 6

outline the use of antigen presentation

Answer 6

• T-cells recognise antigen/ antigen fragment presented on surface of phagosomes
• phagocytes present antigens/ antigen fragments on their surface
• helper T cell recognise them using their specific complementary cell receptor
• the activated helper T cells then clone themselves + release cytokines -> stimulating T killer and B cells -> triggering the immune response

Question 7

give the function of helper T cells

Answer 7

• they recognise the antigen/ antigen fragments presented by phagocytes
• this activates them so they clone themselves + release cytokines -> stimulating T killer and B cells -> triggering the immune response

Question 8

Give the function of killer T-cells

Answer 8

they induce apoptosis in infected cells (make them kill themselves)

Question 9

outline the process of

Question 10

give the function of memory cells