Environmental Influences Flashcards
Microbes have both the fastest and slowest growth rates of any known organism, true or false?
true
These differences are determined by nutrition and niche-specific parameters, true or false?
true (examples include pH and temperature)
What are 4 examples of environmental limits on growth?
1) sea level
2) temperature
3) near neutral pH
4) 0.9% salt and ample nutrients
Organisms that live outside those limits.
extremeophiles
What is the environmental habitat that a species inhabits based on?
the tolerance of the organisms proteins and other macromolecules to the physical conditions within that niche
Using the DNA sequence of a gene to predict the functions of its proteins product.
bioformatic analysis
Why is bioformatic analysis beneficial?
allows us to study biology we cannot culture
Global approaches used to study gene expression allow us to (blank) how organisms respond to change in their environment.
“view”
What does knowing which genes and proteins are expressed in a given situation reveal?
how microbes under different conditions grow and defend themselves
What are microbes commonly classified by?
their environmental niche
Psychrophiles: (growth temperatures)
0-20
Mesophiles: (growth temperatures)
15-45
Thermophiles: (growth temperatures)
40-80
Hyperthermophiles: (growth temperatures)
65-121
Bacterial cells can control their body temperature and it doesn’t match the temperature of its environment, true or false?
false
Changes in temperature impact every aspect of microbial physiology, true or false?
true
The minimum, maximum and optimal temperature.
cardinal temperatures
List some key points about cardinal temperatures.
they define growth range, the typical range spans about 30-40 degrees
Species grow quickly at temperatures where all cell’s (blank) work efficiently.
proteins
Caused by rapid temperature changes during growth that activates groups of stress response genes.
heat-shock response
The protein products of the stress response genes are chaperones. What do they do?
maintain protein shape and enzymes that change membrane lipid composition
Measure of how much water is available for use.
water activity (Aw)
How is water activity measured?
the ratio of the solution’s vapour pressure relative to that of pure water (1)
What are some examples of organism’s water activity levels?
bacteria>0.91, fungi>0.86
