2. Fermentation is the changing of glucose to carbon dioxide and alcohol. The optimum temperature for fermentation is 37 degrees centigrade. With a neutral PH balance of 7. Fermentation is used to create many useful products. Ethanol is an important chemical with a wide variety of uses over 330,000 tonnes is exported every year. Yeast is used to ferment products.

3. Fermentation has been used for thousands of years to produce food and drink. Beer, wine, cider and whisky and foods such as cheese, yoghurt and soya sauce. The newest way of efficiently producing ethanol is to modify the genes of the E.coli virus can produce ethanol from waste biomass such as sugar cane residues, corn husks, wood and other waste organic material.

4. Fermentation occurs when a fungus brakes down the matter in organic material. The fungus changes the glucose into carbon dioxide and alcohol. The container has to be airtight as the ethanol produced will oxidise and turn to an acid. This is how vinegar is made. A carboxylic acid molecule is produced when ethanol oxidises

5. In the process of sewage disposal, sewage is digested by enzymes secreted by bacteria. Solid organic matters are broken down into harmless, soluble substances and carbon dioxide. Liquids that result are disinfected to remove pathogens before being discharged into rivers or the sea or can be used as liquid fertilisers. Digested solids, known also as sludge, is dried and used as fertilisers. Gaseous by- products such as methane, can be utilised as biogas to fuel generators. A major disadvantage of bacterial digestion in sewage disposal is that it is a very slow process.

6. Anaerobic Respiration is Respiration without Oxygen. Yeast uses this for of respiration when there is no oxygen in the atmosphere, this is very useful when making alcohol as oxygen would form a carboxylic acid making a VINEGAR!!!!!