'hexose monophosphate shunt' (PPP/HMP), which has been described in chap. 6, sec. VII. For energy, yield, however, this path is of minor importance. 8

cycle also operates and is called 'pentose phosphate pathway' or 'hexose monophosphate shunt' (PPP/HMP), which has been described in chap. 6, sec. VII. For energy, yield, however, this path is of minor importance. 8. As a result, when the muscle operates (completely/ partially) anaerobically, lactic acid begins to accumulate in the muscle and is then spilled over to the blood. The resting blood lactate value (about 5 mg/100 ml) can shoot upto values like 150 mg/100 ml after a severely anaerobic exercise of some duration (200 m sprinting). 9. Until a few decades ago, it used to be believed that during exercise the muscle depends on carbohydrate catabolism for ATP resynthesis (energy supply). It is now firmly established that during mild or even during moderate exercise, the muscle utilizes fatty acids (not carbohydrate) for ATP resynthesis. It is only during severe exercise, the muscle utilizes the carbohydrate for energy supply. Fatty acids, during their catabolism can produce high amount of energy for resynthesis of ATP (chap. 9, see. VII, energetics in fatty acid oxidation). a smallerAamount of ATP no doubt, but velocity of the total reaction being much faster, the ATP resynthesis from EMP occurs much quicker than that from Krebs cycle. Recall, the number of steps in EMP is, much smaller than that in the Krebs' and hence the velocity is higher. " For details, see chapter on biological oxidation (chap 2 sec VII). I. Introduction II. Classification of exercise