Bacterial Physiology Flashcards
What are the biodegradative pathways and biosynthetic pathways used by bacteria?
DEGRADATIVE: catabolism, produce ATP, acids, bases, and gases
SYNTHETIC: anabolism, consume ATP and produces proteins, lipids, nucleic acids, or polysaccharides from nutrient precursors
What are the main 2 ways that bacteria produce energy?
- fermentation (anaerobic, glycolysis) - results in the production of acids
- respiration (oxidation, oxidative phosphorylation) - results in the production of bases
How does anaerobic respiration produce hydrogen?
use organic compounds, like sulfate and nitrate as electron acceptors
Glycolysis:
glucose-1-P —> pyruvic acid —> fermentation - lactic acid
—> acetyl-CoA —> TCA cycle
With respect to energy production, what is true about all bacteria?
no matter the organism, they all are able to utilize basic components and building blocks to produce acids and CO2
Electron Transport Chain:
Most bacteria are chemoheterotrophs. What does this mean?
they secure electrons for their energy and carbon sources from organic compounds
What are the main products obtained from amino acids, nucleotides, and alcohols (precursors)?
AA - proteins
NT - nucleic acids
A - polysaccharides and lipids
In what way are most bacteria described in relation of temperature?
most bacteria are meophiles - optimal temperature for growth is 30-45 degrees C (10-47 possible)
What are the 4 main divisions of gaseous requirements for bacteria?
- aerobic - requires oxygen for respiration
- anaerobic - requires NO oxygen for fermentation (oxygen byproducts can be toxic since they do not have superoxide dismutase)
- facultative anaerobe - grows with or without oxygen
- microaerophile - requires a reduced amount of oxygen for growth
How do facultative anaerobes typically produce energy?
fermentation/acid formers
- can grow better in the presence of air
How do aerobes typically produce energy?
oxidizing sugars, forming NO acids
How are certain aerobes able to produce energy without utilizing sugars?
utilize nitrogen, sulfure, or other electron acceptors from amino acids or other compounds
What are microaerophiles? Capnophiles? Anaerobes?
bacteria that grow well in the presence of low quantities of oxygen (Campylobacter jejuni)
bacteria that only grow in the air with additional CO2 (Haemophilus)
bacteria that grow in the absence of air and only ferment sugars (Bacteroides)
What are the 2 basic types of culture medium?
- defined/simple (minimal salts) - known quantities of all ingredients; trace elements and vitamins required by the microbe and especially a defined carbon and nitrogen source
- enriched/complex (nutrient broth) - consists of a mixture of many chemical species in unknown proportions
