Cell recongition Flashcards
How can different molecules be detected on an cells
Their 3D tertiary structure
What is an antigen
Molecules that generate an immune response by lymphocyte cells
What will happen if a mutation occurs in the gene thag codes for the antigen
The shape of the antigen will change
What happens when the shape of an antigen changes
Any previous immunity is no longer effective and all the memory cells will remember the old shape so will not work
Describe the process of phagocytes
Non specific response
The receptors on the surface of the phagocyte will attach to chemicals/antigens
The phagocyte changes shape and engulfs the pathogen
The pathogen is contained in a phagosome vesicle
A lysosome fuses with the phagosome and release lysozymes which hydrolyse the pathogen
This destroyes the pathogen
What are lymphocytes
White blood cells involved in the specific immune response
What is the cell mediated response
Once a pathogen has been destroyed it’s antigens are presented on the surface
Helper T cells have receptors on their surface that attach to the antigens on the antigen presenting cells
This activates helper T cells to divide by mitosis and to replicate to make clones which differentiate into different types of T cells
What are the types of differentiated cells that clones T helper cells differentiate into
T helper cells - activate B lymphocytes
Macrophages - for phagocytosis
Memory cells
Killer T cells - cytotoxic
What do Killer t cells do
Destroy abonormal of infected cells
Are antibodies soluble or insoluble
Soluble
What is the humoral response
- B cell is triggered when encountering its antigen
- It takes in the antigen that endocytosus and presents it on its surface
- When the B fell collided with helle T cell it activates it to go through clonal selection
- The b cells undergo mitosis and make large number of cells which differentiate into plasma cells/ memory b cells
Structure of antibody
Quatnernary structure
4 polypeptide chains
What is passive immunity
The antibodies are introduced to the body
What is active immunity
Immunity created by your own immune system following exposure to pathogen or antigen
What is NATURAL active immunity
Following infection and the body creates its own antibodies and memory
What is artificial active immunity
Introduction of a weak pathogen or antigen via a vaccine
What is herd immunity
If enough of the population is vaccinated the pathogen cannot easily be spread amongst the population
How does HIV replicate in Helper T cells
The T cells have CD4 protein which HIV attaches too
The HIV protein capsule fuses to the helper T cell and allows the RNA and enzymes from HIV to enter
The HIV enzyme reverse transcriptase copes the RNA into DNA copy and moved it the the Helper t cell nucleus
What is AIDS
When replication viruses in the helper T cell interfere with the immune system
What is monoclonal antibody
A antibody that can be isolated and cloned
When is it used
Pregnancy tests
Medical treatment/ diagnosis
What can monoclonal antibodies do
They have a binding site complementary to the antigens on the outside of the cell
The antibodies attach to the cell
What is the ELISA test
First mobile antibody ( complementary to the antigen tested for )
Second antibody which is conplemsgeh but is immobilised
Third antibody is immobilised and is complementary to the first antibody
Add test sample to the beaker
Wash to remove ant unbound test sample
Add first antibody
Wash
Add second antibody
