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Bacterial Metabolism and Energy Generation

Terms in this set (41)

Metabolism
sum of all chemical reactions occurring within a cell.
Catabolism
the breakdown of larger, more complex molecules into smaller, simpler ones during which energy is released.
Anabolism
the synthesis of complex molecules from simpler ones during which energy is used
How is metabolic efficiency maintained?
it is maintained by the use of a few common catabolic pathways, each degrading many nutrients
True or False: Microorganisms are catabolically uniform, but are anabolically quite diverse
FALSE.

Microorganisms are catabolically DIVERSE, but are anabolically quite UNIFORM
Oxidation
loss of electrons; results in generation of energy
Reduction
gain of electrons
requires energy
Redox Reactions
involving the transfer of electrons from a donor to an acceptor
Reducing agent
reductant = donor of electrons
Oxidizing agent
oxidant = acceptor of electrons
What is the electron transport chain?
a series of redox reactions that establishes an electrochemical gradient across a membrane that results in the formation of ATP.
What is another term for electrochemical gradient?
proton motive force
What are some examples of donors in the electron transport chain?
NADH
NADPH
FADH2
True or False: Reduced coenzymes (NADH and FADH2) generated in glycolysis and TCA cyles must be reoxidized
True.
True or False: Prokaryotes use the same electron carriers as eukaryotes
FALSE.

They use DIFFERENT carriers; their cytochromes vary
Where does electron transport occur in bacteria?
the cytoplasmic membrane
Where does electron transport occur in eukaryotes?
the inner membrane of mitochondria
What drives ATP synthesis?
the proton-motive force
How is the shuttling of protons across the membrane convert to chemical energy?
by the phosphorylation of ADP to ATP; furthermore those high-energy phosphate bonds in ATP can be used in biosynthetic pathways
Oxidative phosphorylation
a metabolic pathway in which the oxidation of coenzymes and the transfer of their electrons across the membrane allows ADP to get phosphorylized into ATP.
What's the difference in Yield of ATP between glycolysis+aerobic respiration and anaerobic organisms using glycolysis?
Glycolysis+aerobic respiration have a theoretical maximum of 38 ATP/glucose

Anaerobic organisms using glycolysis can only produce 2 ATP/glucose
What's the Terminal Electron Acceptor in Aerobic respiration?
O2
What's the Terminal Electron Acceptor in Anaerobic respiration?
SO4, NO3, CO2
Pasteur Effect
Switch from fermentation (anaerobic) to aerobic respiration when oxygen is available
Fermentation
Electrons and protons from oxidized substrates are transferred directly to another organic compound in the pathway
- no electron transport
- substrate-level phosphorylation used instead
Why must NADH still be oxidized even during anaerobic respiration?
Because the supply of NAD+ used in glycolysis must be replenished
True or False: Fermentations are reactions that regenerate NADH from NAD+ in the absence of oxygen
FALSE.

Fermentations regenerate NAD+ from NADH in the absence of oxygen
What are electron acceptors in fermentations?
pyruvate or pyruvate derivatives
True or False: In fermentation, organic compounds are the electron donors AND acceptors
True.
What's another name for the Embden-Meyerhof pathway?
the glycolytic pathway
In glycolysis, one glucose yields how many pyruvate?
2
In glycolysis, how many ATP is used?
2
In glycolysis, how many ATP in generated?
4
In glycolysis, how many NET ATP is yielded?
2
In glycolysis, how many NAD+ are used?
2
In glycolysis, how many NADH are generated?
2
What are lipids degraded into?
- glycerol
- free fatty acids
What two ways are amino acids removed?
deamination & transamination
True or False: synthesis of amino acids begins with metabolic pathway intermediates of glycolysis or Kreb's cycle
True.
True or False: When microbes growth they increase their cell size
FALSE.

When microbes grow they increase in number, not cell size.
What are some factors that regulate microbial growth?
- Nutrients
- Environmental conditions (i.e. temperature, pH, osmotic pressure)
- Generation time
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