Immunity Flashcards
What is a pathogen?
A disease causing micro - organism
Describe phagocytosis?
- pathogen releases chemicals which attract the phagocyte
- phagocyte engulfs the pathogen
- phagosome forms around the pathogen
- lysosomes inside the phagosome release lysozymes which hydrolyze the pathogen
What is the difference between humoral and cell mediated immunity?
Cell mediated only happens within a cell and humoral is general imfections
Describe the humoral response
- phagocyte presents antigens on its surface
- T helper cell binds to the antigens
- this activates the T cells and they divide by mitosis
- B cell processes antigens and presents them on its surface
- The helper T cells attach to antigens on the B cell and activate it
- The B cell activates and divides by mitosis to produce clones
- The cloned plasma cells secrete antibodies
- Some turn into memory cells which respond to future infections
describe the cell mediated response?
-an antigen presenting cell presents antigens
-A helper T cell binds to these antigens
-The T cell is activated and clones by mitosis
-The T cell stimulates the production of
Helper T cells
Memory T cells
b cells
Cytotoxic T cells
What is an antigen?
A glycoprotein on the cell membrane which stimulates an immune response
What is an antibody?
A globular protein which has variable regions
How do memory cells work?
They are made after a primary infection
If the person is infected again the memory cells with recognize the pathogen and produce a much FASTER immune response with A LARGE QUANTITY of antibodies
What is herd immunity?
When a large proportion of the population is vaccinated it stops the likelihood of a non immune person coming into contact with the pathogen because people are immune
Problems with vaccinations?
Antigenic variability
What is antigenic variability?
When the antigens on a pathogen mutate so the memory cells no longer recognise it
How do antibodies destroy pathogens?
- Agglutination
- Neutralization
- Opzonization
What is a monoclonal antibody?
When a single antibody is produced by a single type of plasma cell
How do monoclonal antibodies target specific antigens?
Add monoclonal antibodies complementary to antigen on plate
- add persons blood
- add second set of antibodies with enzyme attached
- if antigen is present antibodies will bind
- the test plate is washed
- a colorless substrate is added, if the enzyme is present it will breakdown the substrate causing a. color change.
