Lecture 5 Flashcards
Environmental Factors of cell growth
Temp, and nutrient availability
Which divisome component forms a ring around the center of the dividing cell
FtsZ
Which divisome component connects the FstZ ring to the cytoplasmic membrane (the anchor)
ZipA
Which divisome component attracts other Fts protein to the divisome (the Recruiter)
FtsA
Which divisome component is involved in peptidoglycan synthesis
Ftsl
Which protein forms the cellular cytoskeleton
MreB
MreB protein is absent in which type of bacteria
Coccoid bacteria
MreB protein is present in which type of bacteria
rod-shaped bacteria
Which phase is the healthiest state of cells for study
The exponential phase
What is cryptic growth
In which phase is the growth rate zero (also when cryptic growth occurs)
stationary phase
In which phase is the growth rate negative
Death phase
What is the advantage of a continuous culture (Chemostat)
Keeps the cells in the exponential phase by controlling the dilution rate and nutrient concentration
….. measures the microbial growth by counting the number of cells (dead and alive) on a grid
(Microscopic count) cell counts
….. measures the microbial growth by counting viable cells in a agar plate
(viable count) Plate count
Describe the great plate anomaly
Even when cells are taken from the same sample microscopic counts will always be higher than viable counts
…. is a simple/non-destructive method of measuring cell mass and number
Turbidimetric method
What type of cells live in very cold or very hot environments
extremophiles
What type of extremophile has an optimal temp of <15ºC and is slow growing
psychrophile
Snow algae and Seaice diatoms are examples of what type of extremophiles
psychrophiles
What type of molecular adaptation is a “cold-shock” protein and is referred to as antifreeze for the cell
cryoprotectant
What type of molecular adaptation increases fluidity at low temps as well as unsaturation/short-chain FAs
Cytoplasmic membrane
What type of extremophile has an optimal temp of <45ºC
Thermophiles
What type of extremophile has an optimal temp of <15ºC
Boiling Springs Bacteria, Hot Springs Cyanobacteria, Hydrothermal Vent Microbes are all examples of
Heat attracted extremophiles
What type of molecular adaptation increases stability at high temps as well as saturation/long-chain FAs
cytoplasmic membrane
