Glycolysis is the breakdown of glucose into pyruvic acid also called EMP pathway after the scientists Embden, Meyerhof and Paranas and is seen in the Cytoplasm. It involves several steps, Glucose in the presence of ATP is converted to glucose 6 phosphate which by isomerisation forms fructose -6- phosphate and by a second phophorylation forms fructose 1- 6 diphosphate.
This fructose 1 -6 diphosphate a 6 Carbon compound breaks up into 2 molecules of PGAL and DHAP both being 3 Carbon compounds. Each compound then by phosphorylation and dehydrogenation combine with IP and NAD to yield 1,3 di PGA and NADH2. The di PGA by dephosphorylatoin gives ATP and’3 PGA which by rearrangement produces 2PGA. Dehydration of 2PGA yields phosphoenol pyruvate which by dephosphorylation give pyruvic acid.
One molecule of glucose yields 2 molecules of pyruvic acid. ATP
calculion :
ATP used – 2 ATP ATP synthesised NADH2 formed = 2 x 3 = 6 ATP
ATP formed = 4 ATP 10 ATP Net gain = ATP synthesised – ATP used 10 - 2 = 8 ATP.