carbohydrates, organic compounds made up of carbon, oxygen, and hydrogen and which include sugars, starch, and cellulose. Of particular interest to the wine consumer are the simple sugar molecules glucose and fructose, which together make up the sugars in grape juice, and which are subsequently fermented into the alcohol which distinguishes wine from grape juice. Sucrose is the sugar molecule made up of glucose and fructose and is manufactured in the leaves of plants, including vines, by photosynthesis. Sucrose can be converted to all other forms of carbohydrates, such as starch, as a storage compound in the roots and trunks, and cellulose, which is present in all cells. Sucrose is also the basic plant biochemical building block, and can be converted to proteins, fats, and organic acids.