Cell recognition and immunity

• the two types of white blood cell are phagocytes and lymphocytes
• the two types of lymphocytes are T cells and B cells
• phagocytosis process:

  A pathogen attaches to the phagocyte via the receptors on the pathogen, the phagocyte engulfs, the pathogen to form a phagosome, the lysosomes in the phagosome release Lyzomes which hydrolyse the pathogen, the hydrolysis products are then absorbed by the phagocyte
• an antigen is a non-self cell
• B cells mature in the bone marrow
• T cells mature in the thymus gland
• T cells are associated with cell mediated immunity
• B cells are associated with humoral immunity
• B cells are referred to as monoclonal antibodies
• The monoclonal antibodies are either plasma cells or memory cells
• plasma cells are a primary immune response and survive for a few days
• memory cells are a secondary, immune response and last in the body for a long time
• when memory cells encounter, the same pathogen, they rapidly divide by mitosis into plasma cells
• The cell mediated immunity response is a pathogen invades, the body, a phagocyte places, antigens from the pathogen onto its cell surface membrane. The receptors on the T cells are complementary to the antigen. This activates T cells to divide rapidly by mitosis to form colones
• cloned tea cells develop memory cells, stimulate phagocytosis, stimulate the cells and activate cytotoxic T cells
• antibodies are proteins, which have specific binding sites to be cells, antibodies are made up of four polypeptide chains, which have too long and heavy chains, and a pair of shorter and lighter chains
• each antibody has a specific binding site to a specific antigen, which is called antigen antibody complex
• endocytosis is when the surface antigens of invading pathogens are taken up by B cells, the B cell put the antigen on its surface, helper T cells are activated by cell mediated response the antigens activate B cells, the B cells divide by mitosis to give a colone of plasma cells, The colon plasma cells produce and secrete specific antibodies that fits onto the antigen of the pathogen, the antibody attaches to the antigen on the pathogen and destroys them some B cells develop into memory cells
• an antibodies, variable region is its binding site
• an antibodies constant region is the rest of the antibody
• monoclonal antibodies are caused by antigen inducing B cells to divide
• monoclonal antibodies are used to treat cancer by them being specific to cancer cells so the antibodies are given to the patients and attach themselves to receptors on the cancer cells, which blocks the chemical signals which control growth and replication
• an ethical issue of monoclonal antibodies is that they are tested on. Mice.
• passive immunity is from an outside source and no direct contact with the pathogen is required
• The two types of active immunity are natural and artificial
• Active immunity is direct contact with the pathogen
• natural immunity is infected from a disease
• artificial immunity is from an external source and an example is vaccination
• in order for vaccination to be successful the vaccination must be available in large quantities, have a few side effects and transporting storing and packaging must be available
• Herd immunity is when a large population have been vaccinated, making it difficult for the pathogen to be spread
• ethical issues of herd immunity are side-effects, health risks and it can be expensive
• HIV, replicates by the HIV binding to the CD4 protein, the HIV attaches to the helper T cells, the HIV protein capsid fuses with the cell surface membrane RNA and enzymes from HIV. Enter the T cell the enzyme reverse transcript converts RNA to DNA. Then the HIV DNA creates mRNA, which allows for replication.
• an Eliza test uses antibodies to detect proteins
• The procedure of the Eliza test is apply sample to which all antigens attached to wash to remove unattached antigens. Add antibodies that specific to antigen that we wanted detect wash again and add second lot of antibodies and how strong the colour is.