Biology 2:cells - the immune system Flashcards
what are the two types of leukocytes (WBC)
phagocytes
lymphocytes (killer t cell and b cells)
what is a non specific response and what type of response is carried out
immediate response and the same for all pathogens
physical or chemical attacks
phagocytosis
what is a specific response and what type of response is carried out
slower response as it is targetted
cellular response
humoral response
name the two types of cells that perform phagocytosis
phagocyte
macropahge
explain the 7 steps of phagocytosis
pathogen releases chemicals that attract the phagocytes
phagocyte engulfs pathogen
the pathogen is then enclosed in a phagosome(vesicle)
lysosomes in the phagoccyte contain enzymes called lysozyme
lysozyme fuse with the pathogen and break it down
the pathogen is then absorbed
antigens are left and then presented on the cell surface
what are lymphocytes
special wbc that recognises specific antigens on the surface
name the 5 steps in cellular response
macrophage will present antigens on its surface
it odes this by having Mhc lock onto antigens and push it to its surface forming mhc +antigen complex
helper t lymphocytes recognise the mhc + antigen complex using a receptor called cd4
t helper cells then clone themselves and release signalling chemicals called cytokines
cytokines then trigger immune response
how do cytokines trigger immune responses
lymphocytes becoming memory cells
stimulates b lymphocytes to divide
stimulates moire phagocytosis
activates kill t cells(makes holes in cell membrane)
name the five steps in humoural response
pathogen with antigens on its surface is engulfed
this b cell presents the antigen of the pathogen on its surface
t cells come to activate the cell to divide into plasma cells or memory cells
plasma cells then produce antibodies and destroy pathogens
memory cells remember pathogens so if nit return plasma cells are produced quicker
name the 5 features of an antigen
light chain
heavy chain(carboxyl)
antigen binding site (amine group)
hinge regions(disulfide bridges)
name the two regions in a antigen
variable region(binding site)
constant region
name the 3 ways antigens work
opsonisation
neutralisation
complement system
how does opsonisation work
antibodies bind to the pathogen and mark it for phagocytosis
joins together pathogens as it has 2 binding sites and causes them to clump and for phagocytosis to happen quicker
how does the complement system
antibody-antigen complex triggers proteins called the complement system to punch holes in the membrane of a bacteria
what are monoclonal antibodies
produced by a single clone of a specific wbc
what is an eliza test and what are they used for
enzyme linked immunosorbent assay test
used in hospitals to identify specific antigens in blood or fluids
quick and reliable
examples of eliza tests
pregnancy rapid covid prostate HIv
how does a direct eliza work(3 things)
antigen is attached to the surface of plastic when sample is added
monoclonal antibody specific to the antigen is added
antibody has an enzyme attached to it that changes colour
how does a indirect eliza work(3 things)
antigen is attached to the surface of plastic when sample is added
a first antibody specific to the antigen is added and binds to antigen
Wash antigen to remove any excess antigen
secondary antigen is added with a detection enzyme that binds to first enzyme
Was antibody
how does a sandwich eliza work(4 things)
capture antibody is attached to the surface of plastic
sample is added and the antigen binds to capture antibody
secondary antibody is added and binds to the antigen
Wash antigen
third antibody with a detection enzyme binds
Was antigen
What is the difference between primary and secondary immune response
primary is when plasma b cells are cloned and produce antibodies
secondary is when the memory cells are already there and are triggered
what’s the difference between passive and active immunity
passive outside the body
active is inside the body
examples of active and passive
weak or dead pathogen
breastfeeding
what is the goal of vaccination
getting as many people vaccinated(herd immunity
what is hiv
what is a virus outside the body called
a t lymphocyte and is called a retrovirus(has rna instead of dna)
virion
what 2 enzymes does hiv contain and what do they do
reverse transcriptase -converts rna into dna
intergrase - insert dna into host cell
name how hiv works(9things)
hiv attacthemtn proteins bind to dc4 receptor on t lymphocytes
lipid envelope fuses with surface membrane of t cell
virus capsid is taken in by endocytosis
capsid is removed to reveal the rna,reverse transcripotase and intergrase
rna is converted into DNA by the reverse transcriptase
DNA is inseted into the t cells DNA using intergease
new DNA is transcribed into mrna
mrna is sued to make new viral rna and is translated to make a new capsid protein
new virus paricle is assembled and leaves the cell with a piece of t cell membrane around it
how does hiv affect the cellualr response
because there are less working helper t cells
less phagocytosis
less killer t cells
because less cytokines produced
how does hiv affect the humoural response
less triggering of b vells
less antibodies
explain 2 ways on how antibodies work on bacteria
they target DNA replication,metabolism and protein synthesis
punch holes in cell walls
how do we kill viruses and how doi they work
antiretroviral drugs
target virus replication (damages host cells)
name 2 types of antiretroviral drugs
reverse transcriptase inhibitors
protease inhibitors - inhibits hosts protease which are used in viral replication
