9/7 + 9/9 study questions (?) Flashcards
what can act as sources of energy for prokaryotes?
sunlight, inorganic, or organic materials
what do human pathogens use as a source of energy?
what kind of -troph are they?
chemoorganoheterotrophs. organic compounds.
what can act as sources of carbon for prokaryotes?
CO2 or organic compounds
what do human pathogens use as a source of carbon? what are they called?
organic compounds. chemoorganoheterotrophs.
which nitrogen source can be used only by prokaryotes? how do it do it?
atmospheric nitrogen gas (N2) through nitrogen fixation
which nutrient likely limits the growth of cyanobacteria in aquatic environments?
both carbon dioxide and N2
what can cyanobacteria fix? meaning?
?! nitrogen, meaning they can use N2 in the atmosphere.
why would people who have a genetic defect in transferrin/lactoferrin production be more susceptible to certain infections?
transferrin is like an iron vault. to grow in the human body, a pathogen has to acquire iron. if there’s no vault, it’s easier for a pathogen to access iron.
what are siderophores?
ie, what does their name mean?
what are they?
what do they do?
describe their impact on virulency
- “iron carriers”
- small, high affinity iron chelating (to combine a metal compound with a chemical compound) compounds secreted by microorganisms.
- help pathogens acquire free or bound iron
- increased siderophores = decreased virulence of a pathogen
define “fastidious” and name one example of something that is fastidious.
exacting, meaning they have complex nutritional requirements. Neisseria species of bacteria
when would you use a defined medium (aka what?) rather than a complex medium (aka what?)?
DEFINED (aka glucose-salts broth): made of pure chemicals. used in research when type and quantity of nutrients must be precisely controlled.
COMPLEX (aka nutrient broth): don’t know how much of each element is in there. used for routine purposes, easy to make.
what characteristic of a bacterial growth medium makes it differential? give an example of such a medium
includes one or more ingredients that can be changed by certain bacteria in a recognizable way. ex. blood agar to test hemolysis
what characteristic of a bacterial growth medium makes it selective? give an example of such a medium
includes one or more ingredients that inhibit the growth of many unwanted organisms. ex. antibiotic-containing medium, where only antibiotic resistant strains can grow, or phenylethyl alcohol agar
describe MacConkey medium and how it is a selective and differential medium
is blood agar a selective medium?
no, it’s a differential medium
