How glucose breaks down in our body.
Glucose, when completely Catabolized, yields H20 and CO2 plus some energy. A portion
of the energy is converted into ATP and the rest appears as Heat. The catabolic steps may be divided into two traditional major stages, (A) glucolytic pathway (or Embden Meyerhof pathway, EMP); end product of EMP is pyruvic acid or lactic acid, and (B)
Krebs cycle. The end products of Krebs cycle are CO2 and water. There is an alternative path, called the ‘hexose monophosphate shunt or pathway’ (HMS or HMP) by which glucose can be catabolized without going through the EMP. the major aim of HMP is to
generate raw materials for fatty acid, nucleic acid and nucleotide synthesis rather than to generate energy. It will be seen that both the EMP and Krebs cycle can be viewed as mechanisms which cause release of H atoms from the substrates. These H atoms are subsequently carried by hydrogen carrier system so that H20 plus large amount
of energy are formed; the energy is concomitantly trapped and ATP molecules are formed by adding a phosphate radical (phosphorylating) to ADP. Catabolism via HMP occurs notably in adipose tissue as well as in mammary glands and to some extent in the liver. It is to be noted that, in most of the tissues, glucose catabolism occurs andoccurs via EMP; brain, RBC and exercising muscles are only special examples.