Glucose is a carbohydrate, and it is the most simple sugar in human Metabolism. It is called simple sugar or monosaccharide. It is one of the primary molecules which serve as energy sources for plants and animals. Glucose is a sugar with the molecular formula C₆H₁₂O₆. The name "glucose" comes from the Greek word γλευκος, meaning "sweet wine, must". The suffix "-ose" is a chemical classifier, denoting a carbohydrate. It is found in the sap of plants, and is found in the human bloodstream where it is referred to as "blood sugar". The normal concentration of glucose in the blood is about 0.1%, but it becomes much higher in persons suffering from diabetes. When oxidized in the body in the process called metabolism, glucose produces carbon dioxide, water, and some nitrogen compounds and in the process provides energy which can be used by the cells. The energy yield is about 686 kilocalories (2870 kilojoules) per mole which can be used to do work or help keep the body warm.