Explain the Lactate Formation.
At the end of glycolysis 2 NADH+H+ and 2 pyruvate are two of the molecules of interest. During resting and steady state conditions the NADH+H+ molecules go into the inner membrane of the mitchondrion and reduce FAD to FADH2 (NADH+H+ cannot get past the inner membrane). Pyruvate goes directly into the mitochondrion matrix. However, during strenuous exercise the energy demands exceed the oxygen supply in the ETC, causing a back-up in the ETC. NADH+H+ is inhibited and therefore donates its hydrogens to pyruvate, reducing pyruvate temporarily to lactate. NAD+ can then return to Step 6 of glycolysis to pick-up more hydrogens, and glycolysis can continue. Note that 55-70% of the lactate will be converted back to pyruvate and used for fuel in the Cori cycle.
Andrea Schoeny, 2011
Question: Does Lactate Production Occur in the Mitochondrion or the Sarcoplasm of the cell?
Answer: Sarcoplasm of the cell.
Question: What is the cause of acidosis or the 'burn?'
Answer: The production of H+ from the hydrolysis of ATP.