Dextrose: Better known today as glucose, this sugar is the chief source of energy in the body. Glucose is chemically considered a simple sugar. It is the main sugar that the body manufactures. The body makes glucose from all three elements of food, protein, fat and carbohydrates, but in largest part from carbohydrates. Glucose serves as the major source of energy for living cells. It is carried to each cell through the bloodstream. The cells cannot, however, use the glucose without the help of insulin. When sampled in blood, glucose is tested in transit.