Fermentation is an enzymatic controlled anaerobic breakdown of an energy-rich compound. For example, this could be from a carbohydrate to carbon dioxide and alcohol. Certain organisms use fermentation to obtain the energy they need to carry on with life processes. A variety of microorganisms, including yeasts and some molds and bacteria, obtain their energy through fermentation. Fermentation is also results in products that are important for medicines and food preparation. The product of fermentation depends on the type of microorganism and substance that it occurs in. This would occur for example when wine is the product of yeast fermentation in fruit juice.