Cells And The Immune Response Flashcards
Process of phagocytosis
A phagocyte recognises the foreign antigens on a pathogen
The cytoplasm of the phagocyte moves round the pathogen engulfing it
The pathogen is now contained Ina phagocyte vacuole in the cytoplasm of the phagocyte
A lysosomes fuses with the phagocyte vacuole. The lysozyme break down the pathogen
The phagocyte becomes an antigen presenting cell
Activation of T cells
T cell binds to receptors on antigen presenting cell which activates production of T cells
What do helper T cells do
Release chemical signals that activate and stimulate phagocytes and cytotoxic T cells. Activate B cells
What do cytotoxic T cells do
Kill abnormal and foreign cells
What do B cells do
B cells are covered in antibodies. Antibody meets complementary antigen it binds to it. B cells divide into plasma cells
Antibody production
Plasma cells are identical to B cells. They secrete loads of antibodies specific to the antigen. These are monoclonal antibodies
Agglutination is
The clumping of pathogens. Two pathogens bind to one antibody
How does hiv harm the body
Kills helper T cells so other cells in the immune system are not activated - no B cells so no antibodies
What is the latency period of hiv
Hiv replication drops to a lower level - no symptoms
Symptoms of aids
Minor infections of mucous membranes Recurring respiratory infections Diarrhoea TB Toxoplasmosis of the brain
Structure of hiv
Attachment protein Envelope Capsid RNA Reverse transcriptase
Hiv replication
Attachment protein attaches to receptor molecule on the membrane of the host helper T cell
The capsid is released into the cell where it uncoats and releases the rna into the cells cytoplasm
Reverse transcriptase makes complimentary strand of DNA from the rna
Inserted into DNA of host cell
Host cell enzymes make viral proteins from viral DNA
Viral proteins assembled into new virus
How do antibiotics work
Interfere with bacterias metabolic reactions. They target bacterias enzymes and ribosomes
What are antigens
Molecules that can generate an immune response when detected by the body
What are pathogens
Organisms that cause disease
