MUSCLE PHYSIOLOGY

Detailed explanation-1: -Two pyruvates are converted to two lactic acid molecules, which ionize to form lactate. In this process two NADH + H+ are converted to two NAD+. Our muscle cells can undergo this process when they are in oxygen debt.

Detailed explanation-2: -These gluconeogenic substrates are either generated in the liver or delivered to the liver through the circulation from extrahepatic tissues. Lactate is oxidized by lactate dehydrogenase to generate pyruvate. Pyruvate is transported into the mitochondria and converted to oxaloacetate by pyruvate carboxylase (Fig. 1).

Detailed explanation-3: -It is produced in the liver, muscle cells, red blood cells, etc., via fermentation (break down of glucose anaerobically). It is produced in the case of vigorous exercise when the body breaks down glucose without oxygen.

Detailed explanation-4: -The process of fermentation results in the reduction of pyruvate to form lactic acid and the oxidation of NADH to form NAD + . Electrons from NADH and a proton are used to reduce pyruvate into lactate.