Quick topic 4

What’s an inanimate object that pathogens can survive on, resulting in transfer to a new host?

Fomite

What is the main defensive plant molecule?

Callose

What are cytokines and what do they do?

Small molecules involved in cell signalling, help raise body temperature, attracts phagocytes

Explain how blood clots (4)

Thromboplastin released

Prothrombin converted to thrombin

Catalyses fibrinogen → fibrin (insoluble)

Seratonin also causes smooth muscle to contract

Which cells release histamines

Mast cells

What do histamines do?

Cause swelling

What do monocytes become?

Macrophages

Which is long lived: neutrophil or macrophage?

Macrophage

What are cell surface glycoproteins that bind to antigens and display them for recognition by T-cells?

MHC

Which cells display MHCs?

APC

What steps are followed by all lymphocytes (3)

Antigen presentation

Clonal selection

Clonal expansion

What do B-effector cells become?

B plasma cells - produce antibodies

What do t-killer cells do?

Produce perforins that stimulate apoptosis in infected cells

What are antibodies that coat pathogens for recognition by phagocytes?

Opsonins

Which antibodies clump many pathogens together?

Agglutinins