immunity Flashcards
(18 cards)
lymphocytes
B and T
involved in immune response (
Involved in antibody production and immunity
memory b cells can last for years
some glycolipids and glycoproteins act as antigens
ficks law rate of diffusion is proportional to
(concentration gradient x surface area) / thickness of membrane
what do non-self antigens stimulate?
an immune response
what do phagocytes do after engulfing and digesting a pathogen
phagocytes transfer the antigen of digested pathogen to their cell surface membrane becoming an antigen presenting cell
antibody structure
4 polypeptide chains
2 heavy chains attached to 2 light chains by disulphide bonds
constant region=region of antibody that doesnt vary within a class of antibody
variable region=
variable region
different for each antibody
where an antibody binds to an antigen to form an antibody-antigen complex
at the end of the antibody is the antigen binding sites vary greatly allowing for antibody specificity for binding to antigens
apcs
initiates specific immune response
presented to T cells
hinge region
where heavy chains are joined by disulphide bridges
flexibility allowing antigen binding site to be placed at different angles when binding to antigens
alternative splicing
different exons can be excluded or included from mature mrna
also occurs to pre-mrna like splicing
code for the extra section of heavy chains in antibodies not attached to lymphocytes removed during alternative splicing- in the non membrane bound antibodies
non membrane bound antibodies get released directly into the blood
membrane bound antibodies
-extra section of polypeptide chain with their heavier chains
-this forms attachment to lymphocytes
-attached to surface of lymphocytes
agglutination
pathogens caused to clump together by antibodies making them easier to engulf by phagocytes and reduces changes of pathogens spreading through the body
what part of antibodies are complementary to the epitome of the pathogens antigen
variable region/antigen binding site
this allows them to bind
antibody function
bind to specific antigens that trigger the specific immune response
pathogens enter host cells by binding to them using receptors on host cell surface how do antibodies prevent this
antibodies can bind to these receptors preventing pathogens from infecting host cells
anti toxins
antibodies can act as antitoxins by binding to toxins produced by pathogens neutralising the toxins
primary immune response
non-specific followed by specific
numbers of T and B cells with correct membrane receptors present in the blood will be low since its the bodies first time encountering this pathogen
it will take time for correct T and B cells to be activated and divide and differentiate into different cell types
can take days for plasma cells to develop and start producing antibodies against an antigen
so an infected person will experience symptoms of a disease the first time they contract it
both b and t cells produce memory cells during primary response which will remain in the blood after an infection is over
presence of memory cells means theyre immune to that pathogen
secondary immune response
-faster and stronger than primary immune response
-memory cells present inlarger quantities than the mature lymphocytes at the start of primary response
so the correct memory cells are able to detect an antigen, activate, multiply by mitosis and differentiate much quicker
antibodies produced much more quickly and in larger quantities than in primary immune response
this will often eliminate the pathogen before the infected person can show symptoms
