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Cell metabolism

Nitrogen FixationNitrogenaseN2 + 8H → 2NH3 + H2
NitrificationNH3 + O2 + 2H+ + 2e- → NH2OH + H2O → NO2- + 4 e-
GlycolysisC6H12O6 + 2NAD+ + 2ATP → 2 pyruvate- + 4 ADP
Alcoholic Fermentation

Hexose → 2 C2H5OH + 2 CO2

Maltose and glucose converted to ethanol and CO2.
Homolactic FermentationHexose → 2 Lactate- + 2 H+
Cell RespirationC6H12O6 + 6O2 —› 6H2O + 6CO2 + ATP
Photosynthesis6H2O + 6CO2 —› C6H12O6 + 6O2

ATP synthase (ATPase, Complex V) is a highly conserved protein which converts pmf into ATP; it catalyzes a reversible reaction between ATP and ADP + Pi. It has 2 parts: F1 is a multi-unit piece on the cytoplasmic side, and Fo spans the membrane and is the proton-conducting channel.

  • NADH and FADH2 are e- carriers. NADH carries more e- than FADH2.
  • Nitrogen fixation cofactor, MoFe, can change oxidation states. MoFe gets e- from an Fe- protein called dinitrogenase. Haber Process: N2-→NH3 at 400ºC, 200 atm and Fe-catalyst.
  • Anaerobically, SO42- or NO3- are terminal e- acceptors instead of O2.
  • Denitrification reduces NO3- into N2.
  • Chemolithotrophs can oxidize inorganic compounds for energy.
  • Chl is light-sensitive, MG-containing porphyrin initiating photophosphorylation.
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