The glucose obtained by every cell is a carbon compound but not a form of energy that can be directly utilized by the body. So, it is broken down into pyruvate which is a 3 carbon compound to release energy.
Glucose→ 2 Pyruvate + 2 ATP + 2 NADH
The ATP and NADH are energy molecules which can be used by the cells. Pyruvate further undergoes a cycle of changes to release more energy and carbon dioxide. The energy obtained in this process is utilized by the cells.
Pyruvate→6CO2+Energy