Bacterial Metabolism, Nutrition And Growth Flashcards
(28 cards)
Metabolism
All chemical processes that go on in the cells for them to continue living and to reproduce
Requires energy production and making cell necessary materials (enzymes, structural proteins, etc) using the captured energy
Energy production is Catabolism
Building needed complex material is anabolism
Catabolism
Production of energy from organic molecules
Breakdown of complex molecules (substrates) into simpler ones, proteins into amino acids and capture energy
Some sources of substrates include photosynthesis by some bacterial organisms, breaking down and decomposing dead organic matter and waste materials, breaking down or oxidation of chemical compounds, establishment of relationships with other organisms in the form of parasitism or commensalism
Anabolism
Synthesis of macromolecules from building blocks; Enderogenic
How do microbes obtain the organic matter they use for metabolism?
Aerobic Respiration
Results in complete breakdown of glucose to carbon dioxide, water and a lot of ATP
Anaerobic Respiration
Only partially breaks down glucose, into pyruvic acid and organic waste products and a little bit of ATP
Fermentation
When there is no final oxygen for the ETC, the electron transport cannot happen
Fermentation is an alternative system that allows glycolysis to continue without the other steps of respiration
Not as energetically efficient as respiration
Produces only 2 ATP
Steps of glucose catabolism:
-The energy generating patterns involve any of the following depending on the organism: glycolysis, fermentation, TCA cycle, HMP pathway
Define Bacterial Growth
Diffusion
No expenditure of energy
Simple Diffusion
Movement occurs with the concentration gradient; no carrier proteins
Facilitated Diffusion
Carrier proteins bind and transport molecules across the cell membrane
Active Transport
Energy derived from proton motive force; nutrient unaltered
Group Translocation
Energy derived from ATP; nutrient enters cell in altered state
Psychrophiles
-1 to 25 degrees Celsius [15 degrees]
Low temperature food spoilage
Mesophiles
10 to 45 degrees Celsius [35-40 degrees]
Optimum temp 25-40 C
Many human pathogens have optimum 37 C
Thermophiles
40 to 75 degrees Celsius [50 - 60 degrees]
Can live in hot water, Pseudomonads in hot tubs, hot water lines
Bacterial Multiplication
Bacteria divide by binary fission
Lag phase of bacterial growth:
First is the lag phase, vigorous metabolic activity occurs but cells do not divide
Log phase
Rapid cell division occurs in this phase
The stationary phase
Occurs when nutrient depletion or toxic products cause growth to slow until the number of new cells produced balances the number of cells that die
The death phase
Is marked by a decline in the number of viable bacteria
Which of the following is not true about anaerobic respiration?
It involves glycolysis only
Aerobic respiration differed from anaerobic respiration in which aspect?
The final electron acceptors are different
