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| Lactate Formation Story: Class, write out the story in bullet form or paragraph. However is best for you. Make sure you discuss STEADY state and STRENUOUS exercise conditions. CLICK HERE for a YOUTUBE video that explains the Lactate Formation Story 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. Question: What is the fate of the lactate formation? Answer: 50-75% of the lactate will be converted back to pyruvate (in the liver) and used for fuel in a process called the Cori cycle. |
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| Lactate Formation Story Written in Paragraph Form | ||||||||
| At the end of glycolysis 2 NADH+H+ and 2 pyruvate are two of the molecules of interest. During 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 to be oxidized. 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 50-75% of the lactate will be converted back to pyruvate and used for fuel in the Cori cycle. Andrea Schoeny, 2011 |
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| Shuttle of NADH +H+ to FAD in the Mitochondrion in Steady State Conditions | ||||||||
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| Inhibited Shuttle of NADH +H+ to FAD in the Mitochondrion in Strenuous Exercise Conditions | ||||||||
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