prokaryote ecology Flashcards
1
Q
Leibig’s Law of the Minimum
A
- amount of growth of any organism is determined by the nutrient present in the lowest concentration in relation to the requirements of the organism
2
Q
Shelford’s Law of Tolerance
A
- for an organism to grow in a given environment each of a complex set of conditions must remain within tolerance range of that organism
- conditions can interact, affecting tolerance levels
3
Q
studying microorganisms
A
- laboratory
- different behaviour to natural environment
- the great plate count anomaly, >99% not cultured
- total count> viable count
4
Q
how to find optimum conditions for microbe
A
- trial and error, nutrients and conditions
- look at natural environment
e.g. animal pathogens usually need nutrient rich environments at body temperature
5
Q
psychophile
A
0-20C
6
Q
mesophile
A
15-45C
7
Q
thermophiles
A
- moderate thermophile = 40-70C
- extreme thermophile bacterium = 65-100C
- extreme thermophile archaea = <120C
8
Q
minimum temperature for growth
A
- membrane gels, becomes solid
- transport processes across membrane so slow growth cannot occur
- reversible
9
Q
optimum temperature for growth
A
enzymatic activities at maximum possible rate
10
Q
maximum temperature for growth
A
- thermal lysis, membrane too fluid
- protein degradation
- more consequences, less reversible
11
Q
acidophile
A
pH 1-5
12
Q
neutrophile
A
pH 5-8
13
Q
alkalophile
A
pH 9-12
14
Q
acidophiles and alkophiles
A
- cells internal environment remains near neutrality, regulated by H+ pumps
15
Q
halophiles
A
can tolerate higher concentration of NaCl than sea water
16
Q
microbiome
A
all of the microorganisms within a specific environment
- play an important role in control of vital homeostatic mechanisms in the body
17
Q
roles of microbiome inn human body
A
- protection against pathogens
- synthesis of vitamins
- development of immune system
- promotion of intestinal angiogenesis (new blood vessel growth)
- promotion of fat storage
- short chain fatty acid production by fermentation of dietary fibre
- modulation of CNS
18
Q
microbiome of giant tubeworm
A
- have no mouth or digestive system
- obtain all energy and nutrients from mutualistic bacteria through chemoautotrophy
- small symbionts in middle divide and help with sulphur storage
- large symbionts on periphery fix CO2
