The catabolic reactions involved in the oxidation of glucose can be divided into several shorter sequences of reactions. The transition reactions remove carbon dioxide and hydrogen from pyruvate, producing acetate. The acetate, when lilnked to a molecule of coenzyme A, forms acetyl coA, and is ready to be fed into the Krebs cycle.
Energy is stored in the chemical bonds of the molecule.
It is this energy that the cell must trap, in the form of ATP, in order to fuel its needs. ATP, or adenosine tripohsphate, is often referred to as the cell's energy currency'. It is a small molecule, a single nucleotide bearing additional phosphate groups. Each extra phosphate group is connected to the molecule by a high energy phosphate bond. All cells are capable of glycolysis, and use the same metabolic pathway to convert gflucose to pyruvate, extracting chemical energy.