Ans.
Glycolysis is an universal metabolic process that takes place in cytosol of all living cells. It involves breakdown of glucose molecules into pyruvate to produce energy in the form of ATP as during glycolysis, one glucose molecule is converted into two pyruvate molecules, and 2 ATP molecules and 2 NADH molecules are released.
Thus, 'the main transformation that takes place during glycolysis is breakdown of glucose molecule into pyruvate, NADH and ATP molecules.'