Chapter 6 (EXAM 2) Flashcards
Viable count
The number of microorganisms in a particular media that are alive
Total count
The number of microorganisms in a media that are both living and dead`
Generation time
The time for a cell to divide and population to double; species specific
The rate is always constant \
What is the growth curve and its phases
The curve of microorganisms in unnatural environment, not soil or water
Phases are lag, log, stationary and death
Lag phase
Little to no division of growth in bacteria
Turn genes on that were silences
Once they’ve gotten enough food they move to next phase
Log phase
Exponential increase in population
Industrial producers will create a condition of hemostatic environment(constant)
Stationary phase
When resources become scarce, the number of dying cells dont equal the number of cells dividing
At the end you see less growth, organisms are smaller then normal
Death phase
Organisms planning for death of population and produce endospores if the bacteria is able to
What phases are exponential
Log and death
What are plasmids
What bacteria pick up at later stationary phase and beginning of death phase in desperation to survive.
Tiny circles of genetic material that contain genes of resistance
What are growth influences of cells
Cells require water bc it aids in diffusion of materials
Like less then 1% salt, about .85 NacI
Applies to most bacteria except staph and hydrophilic archer bacteria can tolerate higher salt solutions
what does it mean to be phacotactive
Be on a needs basis with or without salt
Isotonic
Same on the outside as it is on the inside
Hypertonic
Enviroment is more concentrated in solutes on the outside
Water goes out cell then what’s inside the cell
Hypotonic
Solution cell is in is more watery compared to what’s inside of the cell. Cells take more water in
Describe psychrophiles
Cold organisms that can live btwn -10 & 20
15 being optimum temp
Describe psychrotrophs
Cold loving organism that can go in fridge range in 0-30
25 being optimum temp
Describe mesophils
Live within 10-50 range
37 being their fav temp ( body temp)
Describe thermophils
Like warm temp. Live in compost piles, dump, heat resistance
Live in 40-72 range, 62 being their fav temp
Describe hyperthermophils
Type of archer, extreme bacteria
Like temperature of 67-110, 94 being fav temp