Antibodies and T-lymphocytes Flashcards
Antibodies are…
globular glycoproteins with quaternary structure.
An immunoglobulin is a group of…
plasma proteins formed of antibodies.
Each antibody is made of…
4 polypeptide chains. Two ‘long’ or ‘heavy’ and 2 ‘short’ or ‘light’.
The chains are held together by…
disulfide bonds.
Each antibody has two…
identical antigen-binding sites. These are variable regions, which is different on each type of antibody produced.
An antibody has a hinge region which…
gives flexibility to antibody to bind around the antigen.
Antibodies combine with viruses and bacterial…
toxins preventing them entering or damaging cells.
Antibodies can attach to…
flagella of bacteria making it less active and easier for phagocytes to engulf them.
Antibodies with multiple antigen-
binding sites cause agglutination(clumping together) of bacteria and prevent spreading.
Antibodies can create holes in…
the cell walls of bacteria, causing them to burst due to osmosis.
Antitoxins are a special type of…
antibodies which combine with toxins and neutralises them.
Mature T cells have a cell…
surface receptors called T cell receptors.
T cell receptors have a similar…
structure to antibodies and each specific to one antigen.
Antigen presentation is…
the display of antigens on the cell surface of cells.
Helper T cells when activated…
they release hormone cytokines that stimulate appropriate B cells to divide and develop to plasma cells.
Cytokines also stimulate…
macrophages to carry out phagocytosis more quickly.
Killer T cells search…
the body for cells that have become invaded by pathogen and are displaying foreign antigen on their cell surface membrane.
Killer T cells recognise the antigen and…
attaches to the surface of infacted body cell and release toxins which kill both the body cell as well as the antigen.
Memory cells of…
helper T and killer T cells are produced.
The number of neutrophils increases during…
bacterial infections and whenever some tissue becomes inflamed.
The number of lymphocytes increases when…
viral infections are presented.
Two types of bone marrow stem cells:
myeloid and lymphoid.
Myeloid stem cells divide into…
neutrophils, monocytes and platelets.
Lymphoid stem cells divide into…
lymphocytes both B and T
Leukaemia is…
a cancer of bone marrow stem cells.
Leukaemia causes disruption…
in the production of red blood cells and platelets. Causes anaemia and the risk of excessive bleeding.
Leukaemia also increases the number of…
mature neutrophils and lymphocytes, making the person more vulnerable to infections.(immunosuppressed)
