Microbiology Flashcards
how do bacteria reproduce
binary fission
what does FtsZ do
forms a ring to start cell division
what is bactoprenol
a transporter for cell wall building
what happens in the lag phase
cells prepare to divide
what is log phase
rapid growth
what is stationary phase
growth and death equals out
what is the primary structure of bacteria cell walls
peptidoglycan
whats the protective layer outside the bacteria wall called?
capsule
what limits bacterial growth
nutrients and waste
whats turbidity?
a measure of bacterial density using light
what are transpeptidases
enzyme that cross-links peptidoglycan
what is j.waston famous for
co discovering DNA structure - helix
what is mary lyons famous for
concept of x-chromosome inactivation
what is F. Griffith famous for
discovering bacterial transformation
what is e. tatum known for
genes control biochemical reactions
primary component of bacteria cell wall?
peptidoglycan
function of glycocalyx
adherence, water loss protection
Whats a well defined layer of glycolax on a bacteria called?
capsule
Whats a less defined layer of glycolax on a bacteria called?
slime layer
what enzyme targets peptidoglycan
lysozyme
whats the primary stain used
crystal violet
why do gram pos retain blue
thick layer of peptidoglycan traps the crystal violet-iodine
what dissolves the lipid layer in gram neg
ethanol
why dont gram neg stay blue
ethanol washes away the thin layer of peptidoglycan washing out the blue
what occurs with gram neg when ethanol is applied
dissolves the layer of lipids allowing crystal violet-iodine to be washed out
what occurs when ethanol is applied to gram pos
it dehydrates the thick peptidoglycan layer, shrinking it trapping the blue
why do gram neg stay red
after the crystal violet is washed away, safranin changes it from colourless to red
how many membranes do gram neg have
2
how many membranes do gram pos have
1
why doesnt safranin affect gram pos
the blue overpowers the red
whats chemotaxis
movement to or from a chemical signal
what are endospores
dormant, resistant structures formed by bacteria
which genera are known for endospores
bacillus and clostriduim
what triggers spores
favorable environmental conditions
what are subunits of 70s ribsomes
50s and 30s
