Microbio Essential terms Flashcards
Peptidoglycan
component of cell wall; gram + have lots, gram - have little
Glycocalyx
sticky secretion of polysaccharides and/or polypeptides that helps bacteria attach to the host; capsule = firmly attached, slime layer = soluble loose layer; prevents desiccation; also aids in formation of biofilms because other bacteria can stick to it
Virulence
the ability to cause infectious disease
Virulence factor
something that the bacteria possesses that makes it able to infect and cause disease
Monotrichous
one flagellum
Amphitrichous
one flagellum at each end
Lophotrichous
multiple flagella at each end
Peritrichous
flagella all over
Taxis
bacterial movement; run = flagella rotate counterclockwise, tumble = clockwise
Axial filaments
ilaments between the outer layer and cell membrane which make the bacteria move like a corkscrew; advantageous because no antigens; example in spirochete; enable easier burrowing through mucous layers etc.
fimbrae
little projections, not flagella or cilia; proteinaceous, bristles; sticky due to adhesion proteins at their ends; used to attached to host or to pull bacteria along; also important in biofilms
NAG
sugar in peptidoglycan
NAM
sugar in peptidoglycan
Gram positive
category of bacteria that have a thick layer of peptidoglycan in their cell wall which binds the stain and appear purple
Gram negative
category of bacteria that have a thin layer of peptidoglycan in the cell wall and numerous liposaccharides; when stained, the liposaccharides come off and the dye that entered the cell leaks out so it doesn’t stain; appear pink
Teichoic acid
polyalcohol in peptidoglycan of gram + bacteria
Lipoteichoic acid
polyalchol attached to lipid in cell membrane; attaches peptidoglycan to cell membrane
Outer membrane
beyond cell membrane; encloses endoflagella in axial filament
Lipid A
Lipid A, part of lipopolysaccharide; released from gram - bacteria when they die
Pyrogen
a chemical that causes fever
Lysozyme
enzyme found in human tears that digests peptidoglycan
Plasmolysis
when a cell becomes dehydrated, the cell membrane
Active transport types
- symport: one compound is actively transported out, which then couples with another molecule and drags it in through another channel passively
- uniport: durr
- antiport: eg Na/K pump
Group translocation
a compound enters a protein channel, but as it is imported it is chemically altered (eg. phosphorylated) so that its concentration gradient does not pull it back out
Inclusion
vacuoles with nutrients stored away
Endospores
highly resilient dormant form of bacteria; formed in response to high stress; made by vegetative bacterial cell which disintegrates after; low metabolism
