Answer to Question #6903 in Organic Chemistry for shelly

Question

A freshman studying medicine at an Ivy League College is a part of his class crew team and exercises regularly. After a particularly strenuous exercise session, he experiences severe cramps in his thighs and pain in his biceps.

* Explain the chemical process that occurred in his muscle cells to cause this discomfort.


* Explain the chemical reactions that have possibly taken place in his body after the exercise.


* Discuss possible treatments for the freshman and how the treatment works chemically.

Answer 1

During power exercises such as sprinting, when the rate of demand for energy is high, lactate is produced faster than the ability of the tissues to remove it, so lactate concentration begins to rise. This is a beneficial process, since the regeneration of NAD⁺ ensures that energy production is maintained and exercise can continue.

*During intense exercise, the respiratory chain cannot keep up with the amount of hydrogen atoms that join to form NADH. NAD⁺ is required to oxidize 3-phosphoglyceraldehyde in order to maintain the production of anaerobic energy during glycolysis. During anaerobic glycolysis, NAD⁺ “frees up” when extra nonoxidized hydrogens combine with a pyruvate molecule and then form lactate. If this does not occur, glycolysis comes to a stop. However, there is lactate being continually formed at rest and during moderate exercise. This occurs due to the metabolism of red blood cells that do not have mitochondria and limitations resulting from enzyme activity that occurs in muscle fibers that contain a high glycolytic capacity.

*The increased lactate produced can be removed in a number of ways, including: Oxidation to pyruvate by well-oxygenated muscle cells. Pyruvate is then directly used to fuel the Krebs cycle. Conversion to glucose via gluconeogenesis in the liver and release back into the circulation; If not released, the glucose can be used to build up the liver's glycogen stores if they are empty.