During cellular respiration, which is a part of metabolism, one molecule of glucose produces a maximum yield of 38 molecules of ATP (adenosine triphosphate). ATP is the energy form that cells use to function and has also been often called the "currency" of the cells.
The whole process begins with breakdown of food by the digestive system right down to their monomer units. Carbohydrates are broken down into glucose, which is carried by blood to all cells of the body.
Each cell takes in glucose and breaks it down through the respiration process that begins with glycolysis in the cytoplasm which yields 2 ATP molecules, then onward into the mitochondria of the cell where Krebs cycle and electron transport chain processes generate 34 to 36 more molecules of ATP.
