micro-organisms summary Flashcards
what are moulds?
they are filamentous fungi that cause superficial infection but can be systemic e.g. aspergillosis
what do moulds form?
a mat of mycelium - this may have a septate
what are multiple fungal cells?
mycelium - collection of hypha
how do moulds replicate?
the mould spore are produced in the sporangium and it depends on the type of tissue that you have as to whether there is a fruiting body produced as well
what size are helminths?
they are macroscopic
what types can helminths be?
intestinal or non-intestinal but these can migrate to the intestines
what are protozoa?
they are eukaryotes that arent plants or fungi
what do ciliates have?
cilia outside their cells
what do flagellates have?
flagella on surface to aid movement
what is acomplexa?
special bodies to infect certain things
how do parasites replicate?
can have vectors and multiple hosts
what do some parasites form?
cysts - similar to the endospore in bacteria
what do viruses require?
a pay load - RNA or DNA and a host cell to replicate
what is the protein coat made of?
it is a capsid made up of capsomeres
how are viruses classified commonly?
based on symmetry
do viruses have a cell wall?
no - they can be covered in a lipid envelope from the cell membrane of the original cell they infected or can be nakes
how can viruses escape from cells?
they can burst out and escape or bled out and take some of the membrane with them which avoids the immune system of the host
what can RNA strands be?
positive or negative sense
what is required of negative sense before the ribosome and why?
converted to positive sense so can be made into protein
how is positive strand RNA made from RNA?
reverse transcriptase makes RNA into cDNA and then to postivie RNA
how are virus families names?
based on the presence of DNA or RNA
what determines which cells are infected by viruses?
tissue tropisms
how are viruses recognised?
through standard take or receptor mediated endocytosis after attachment
what happens once the virus is in the host cell?
it uncoats and releases genetic material
how are cellular processes of the host cell taken over by the virus?
using intergrase
what are prions?
proteinatious infectious particles
how is a cascade formed by prions?
misfolded proteins can induce other proteins to misfold
what happens to amyloid that is produced?
it aggregates
what is the effect of prion infection?
sponge like holes in the brain - deterioration of brain function
why are prion infections lethal?
they are hard to eradicate and cannot be treated
