Anaerobic Respiration

• If O2 can't be supplied fast enough to accept electrons from electron carriers, NADH and FADH accumulate. The supply of oxidated NAD and FAH soon runout, there are required to accept protons in glycolysis, link and Krebs'. So respiration stops!
• Anaerobic respiration adds an extra step to the end of glycolysis that regenerates oxidised NAD, so allowing glycolysis t continue and net 2 ATP to be made.
• Plants: in some microorganisms the pyruvate loses a molecule of CO2 and accepts the proton from NADH forming ethanol.
• Animals: the pyruvate accepts protons from NADH to form lactate. Build up of lactate causes cramp and muscle fatigue so the lactate must be oxidises back to pyruvate when O2 is available again.