Cell Division
How do bacteria divide?
Binary Fission
Growing just one species of bacteria by itself
Pure culture
Number of cells versus time
Turbidity
Organisms that get energy using oxygen
Aerobes
Microbes that grow at what we consider "normal" temperatures
What is the rate of growth for bacteria?
Exponential (1 --> 2 --> 4 --> 8 etc)
Common method of studying bacteria in the lab is to grow them on the surface of these
Agar plates
Preparing to grow; sensing environmental conditions; making proteins needed
Lag
Organisms that grow without oxygen
Anaerobes
Microbes that prefer lower temperatures
Psychrophiles
What determines how cells will cluster?
Plane of division
Bacteria spend a lot of time not growing or growing slowly- is this true?
Yes
Active growth and doubling; the slope of the line reflects growth rate (steep slope = fast growth; shallow slope = slow growth)
Exponential
Facultative
Microbes that prefer higher temperatures
Thermophiles
This bacteria divides in the same plane each time - becomes a chain of cells
Streptococcus
Do bacteria always double as fast as possible
No
Not doubling anymore; surviving; resisting damage/death; cells have run out of food or built up too much waste
Stationary
Organisms that can only grow in the presence of oxygen
Obligate aerobes
What defensive mechanism does the body have in response to illness (has to do with temperature)
Fever
This bacteria divides in random planes - becomes a cluster of cells
Staphylococcus
What are these: temperature, pressure, pH, oxygen availability
Environmental factors
Cells die and lyse
Death
Organisms that cannot tolerate oxygen at all
Obligate anaerobes
By plotting growth curves of cells growing at different temperatures along with growth rate vs temperature we can determine
Optimal temperature (where the organism grows the best)