Microbiology

Question 1

major groups of human pathogens

Answer 1

protozoa 
fungi 
bacteria
viruses 
prions

Question 2

cell wall

Answer 2

peptidoglycan 
rigid cage structure 
will determine the shape, structure and integrity 
repeated polysaccharide structure 
penicillin targets cross link in PG

Question 3

gram positive

Answer 3

purple
thick multilayer PG
50 layers

Question 4

gram negative

Answer 4

pink
outer membrane - asymmetric, unstable
periplasm - some proteins
thinner PG layer - 3 layers

Question 5

lipopolysaccharide

Answer 5

gram negative - surface of outer membrane
structural role, antigen and bacterial toxin
can result in an inappropriate immune response

Question 6

flagella and fimbriae

pilus

Answer 6

flagella similar to ATP synthase
gram positive fimbriae non flagella protein appendages
gram negative pilus no motor, pilin repeated protein unit

Question 7

aerobic and anaerobic

Answer 7

aerobic - grow in O2
obligate aerobes - requires O2
obligate anaerobes - killed by O2
facultative anaerobes - tolerate O2
capnophillic - prefer high CO2 levels

Question 8

heamolysis - blood agar

Answer 8

streptococcus
alpha - green colonies
beta - heamolysis
gamma - no heamolysis

Question 9

serological tests

Answer 9

host immune response to Ag by raising of Abs
detect presence of specific IgM Ab to virus/microbe
rapid detection of virus

Question 10

parasitic life cycle

Answer 10

adhere colonise and invade
evade host defences
multiply
exit the host

Question 11

virulence

Answer 11

measure the capacity of a microbe to cause damage to the host

Question 12

commensal

Answer 12

organism that is part of the normal gut flora

Question 13

fungal infections

Answer 13

candida most common

Question 14

endotoxin and cytokines

Answer 14

outer membrane of gram negative bacteria
assymetric membrane
bond to receptors on macrophages, b cells, stimulates release of acute phase cytokines

Question 15

endotoxin shock

Answer 15

macrophages or t cells can cause release of inflammatory cytokines

Question 16

mechanisms of fever production

Answer 16

antigen interacts with macrophages 
macrophages release cytokines into bloodstream 
cytokines travel to hypothalamus 
increases body's thermal set point 
fever 
increased survival of infection

Question 17

isosahedral symmetry

Answer 17

made up of repeated subunits, 3 proteins

Question 18

helical symmetry

Answer 18

a single protein subunit repeated

Question 19

virus mechanism

Answer 19

attachment 
entry 
uncoating 
nucleic acid and protein synthesis 
assembly 
release

Question 20

confirmation of virus

Answer 20

detect antibody response not virus itself