Catalysts accelerate the rate of reaction and remain chemically unchanged or burn out in the process and are widely used in industry. Enzymes are biological catalysts made of proteins and can be widely used in industry as they work best near the ambient temperature and pressure that can be maintained in industrial processes. Catalysts accelerate the rate of reaction and can also be used to change the properties of a product to increase its usefulness: they can transform light, flexible poly(ethene) into a denser, less flexible material with a higher melting point . An example of an enzyme used as a catalyst is during the production of ethanol. Ethanol is the alcohol that people drink and is also used as fuel, solvents and as a raw material for other processes. Fermentation uses the enzyme zymase which is an enzyme used in fermentation to break down sugar into ethanol and carbon dioxide. Zymase is a naturally occurring tin yeast present in alcohol production as it breaks down sugars into ethanol with carbon dioxide as a by-product - this is efficient under controlled conditions such as temperature (30°C). Although the method of producing ethanol is renewable because sugar beets and yeast grow rapidly, the reaction has low atom economy and the enzyme is killed by the ethanol produced. However, industrial ethanol production is also a good example of why Le Chatalier's principle is important in real life since ethanol is produced by a reversible reaction between ethene and steam. Iron is used as a catalyst in the Haber process - the reversible production of ammonia, which combines hydrogen and nitrogen. Containing potassium hydroxide as a promoter to increase its efficiency, the use of iron does not make it necessary for use etc...... middle of paper ...... Reducing carbon emissions in cars is a big step forward in the other direction of global warming. Works Cited Aicken, Michael et al. GCSE 21st Century OCR Chemistry. Publishers Coordination Group (CGP). (2007). Page 85. Print. Angelosanto, Antonio et al. AS Level Chemistry. Publishers Coordination Group (CGP). (2008). Page 87. Print.Clark, Jim. "Haber Trial". http://www.chemguide.co.uk/physical/equilibria/haber.html. (2002). NP Network. Date accessed: 24.05.11.Bryant, Charles. “How Catalytic Converters Work.” http://www.howstuffworks.com/catalytic-converter.htm. Np Web. Access date: 05.25.11 Wikipedia. "Catalytic Converters." http://en.wikipedia.org/wiki/Catalytic_converter. Wikimedia Foundations Inc., Web. Date accessed: 05.25.11R, Eric and C, Pete 'Catalytic Converter'. http://www.fordscorpio.co.uk/cats.htm. (2005). Np Web. Access date: 23.05.11