Topic 4: Microbial Metabolism Flashcards
Catabolism
Breakdown of organic molecules so that energy may be gathered
E.x. Glycolysis, Kreb’s cycle
Anabolism
Synthesis of complex organics from smaller “building blocks”
Ribozymes
Modify other RNA molecules
Enzyme effectiveness is affected by
- Substrate concentration
- Enzyme concentration
- Temperature
- pH
- Inhibitors
Competitive Inhibitors
Inhibitors bind at the active site, blocking access by normal substrate
Non-competitive Inhibitors
Inhibitor binds at a different site on the enzyme
- This changes the conformation of the active site, preventing the normal substrate from binding
- Some bind up cofactors
Feedback Inhibition
End-product of a biochemical pathway inhibits the enzyme that mediates an early step of the pathway
Autotroph
Co2, by carbon fixation
Heterotroph
Complex organics (food)
Chemotroph
Energy from Inorganic or organic compounds
Ex: SO4, glucose
Phototroph
Energy from light
Cyanobacteria
Photoautotrophs
Reduction
When a compound gains an electron
Oxidation
When a compound loses an electron
Glycolysis
Extract energy from carbon-carbon bonds found in glucose and stores it as ATP
How is pyruvate metabolized?
Fermentation
- Yields ethanol, lactic acid, etc
- Homo/hetero-fermentative
Homofermentative
Producing a fermentation resulting in a single product
Hetero-fermentative
Producing a fermentation resulting in multiple products
Cellular respiration
Krebs cycle & electron transport chain
Aerobic cellular respiration
Uses O2 as a terminal electron accepter
Anaerobic cellular respiration
Uses nitrate, sulfate
Respiration: transition step
Pyruvate combines with Coenzyme A to yield NADH and Acetyl CoA
- Also gives offf CO2
Krebs Cycle
- Acetyl coA to citric acid
- 2 cycles occur for every glucose molecule metabolized
Electron transport chain
A long chain of compounds being oxidized and reduced by electrons being passed along
- Electrons lose energy each time its passed along
Where does the electron transport take place
Along the plasma membrane
ATPase
Allows the protons back across the membrane
electron transport chain
Fermentation yields__
Ethanol, lactic acid or other products
Pentose phosphate pathway
- Parallel to glycolysis
- Products recycled back into pentose phosphate or into glycolysis
- Bacillus
Entner-Doudoroff pathway
Cleaves glucose to pyruvate and G3P
