August 7, 2012
Enzymes are very precise protein molecules with a high specificity which are used to catalyse chemical reactions by lowering the activation energy required for the reaction to take place. It is these properties of being able to break down substances easily and bind specifically to certain chemicals that make enzymes very useful in many industries and practices throughout the world. In addition to this enzymes are not used up in experiments so products of processes are not contaminated with enzyme which could be a problem. This essay explains 3 uses of enzymes, in industry and food, diagnosing and analysing, and treating disease, explaining the function and advantages of enzyme use in each example. In industry enzymes are used for many processes such as brewing beer, baking bread, using pectinase to increase juice in fruit juice drinks and protease enzymes in washing detergents. Another example of the use of enzymes in industry is animal feeding. Many monogastric species such as poultry are fed food with enzymes added which break down substances in the food which the species body cannot digest. Many foodstuffs for farm animals such as wheat, rye, barley and oats contain non-starch polysaccharides (NSPs) which are an example of ANFs (anti-nutritional factors). They cannot be broken down by the monogastric species so the substance would build up in the body and cause digestive problems leading to other enzymes not being able to function properly. In addition to this NSPs are soluble and so can dissolve in the body but this increases viscosity in the gastrointestinal tract. This tract is vital in the process of digestion, so digestion is inhibited by the increased viscosity. Enzymes can be used however to break NSPs down into smaller products that the body can deal with and digest. The enzymes xylanase is used to break down arabinoxylans in wheat and rye and ß-glucanase enzymes are used to break down ß-glucons in barley and oats. (1, 2 ) Enzymes are very useful in this example as they allow an increased variety in the diet of animals which may mean that farmers get more money when they are sold and they will have higher production efficiency. Other enzymes are now being developed which will have the same effect on ruminant species such as cattle. Another example of enzymes used in industry is the use of phytase which increases the reaction releasing phosphorus from phytic acid in plants. Phosphorus is essential to keep plants alive and if it isn’t released enough then phosphorus has to be added artificially to the plant which causes environmentally polluting waste from the plant. In this case the use of enzymes reduces pollution from plants and increases the utilisation of available nutrients. Enzymes are very useful in industry as they are not used up within a reaction so if they are immobilised they can be re-used. This means they are required in relatively small amounts thus making industrial processes cheaper which is very important. The fact that they reduce activation energy means temperatures can be lower in processes such as brewing beer or in washing detergents. This makes such processes cheaper as less energy is required for reactions to take place. An example of enzyme use for diagnostic and analytical purposes is the use of clinistix to monitor glucose levels in diabetic people so they know how much insulin to inject into their body. This is one example of an enzyme being used as a bio-sensor, which means that it monitors something or detects an amount of something in a mixture of many substances. Enzymes are therefore very useful as they are very specific and can detect even a tiny amount of its complementary substance in a relatively large mixture of many other substances. In the case of clinistix and glucose detection, different enzymes catalyse different reactions to indicate the amount of glucose present. In the body, glucose reacts with oxygen to form hydrogen peroxide, but this can be catalysed by the addition of glucose oxidase which as its name suggests catalyses the oxidation of glucose to increase the production of hydrogen peroxide in a measurable space of time, which is usually too small to measure without the enzyme. Hydrogen peroxide can convert a colourless chemical (hydrogen donor) to a coloured chemical. This process is catalysed by the enzyme peroxidase so a measurable amount of colour change takes place in a sensible space of time. The clinistix are small strips of paper with a cellulose fibre pad on the end within which the glucose oxidase, the colourless chemical and the peroxidase are immobilised onto. Immobilising the enzymes means that they work more effectively as Enzyme Substrate complexes can be formed more readily, the reaction can occur continuously and no allergic reactions of users can occur. The substances are also bounded by a partially permeable membrane which allows glucose to pass through but doesn’t allow any large protein molecules through which may effect the reaction. The darker the clinistic goes, the more glucose was present because more hydrogen peroxide has been available to change the colour of the hydrogen donor. (1, 5, 6, 7) Many other bio-sensors are currently in use such as drug detection used by police to detect drugs such as heroin in a human’s body and pregnancy testing kits. They are now commonly used in conjunction with transducers to give an electrical quantitative analysis rather than quantitative colour changes. Enzymes are very useful in this case as they are helping analyse medical conditions and helping the general quality of life and health of the public and helping prevent crime in drug testing. An example of enzyme use in treating disease is the treatment of blood clots and thrombosis such as deep vein thrombosis. Blood clots are essential as they stop us from bleeding to death but at the same time if a blood clot becomes too big it can block off essential passages such as arteries and veins, this is called an embolism and can be fatal. Examples of thrombosis are deep vein thrombosis in the veins in legs, coronary thrombosis in the heart which can lead to heart attacks, pulmonary embolisms which block breathing passages and retinal vein occlusion which is a large blood clot in the eye. Thrombolytic treatment involves enzymes which are used to break down the fibrin molecules which make up blood clots and cannot be broken down naturally in the body. The enzymes used are sometimes referred to as ‘clot busters’. Examples of enzymes used are reteplase, alteplase and streptokinase. These can be introduced to the body using an intra-venous line or simply injected, however if the enzyme is required rapidly for example if a person has had a heart attack then enzyme infusion may take place which uses a catheter to inject more concentrated enzyme directly into the clot so the fibrin is broken down faster. (1, 3, 4, 8) Enzymes are very useful in this example as they can safe lives due to their high specificity and ability to increase the rate of reaction to degrade the fibrin before the person dies. If the enzyme was not substrate specific then when it was injected into the body rather than directly into the clot in may catalyse other reactions thus making it take longer to get to the blood clot. There is however a disadvantage in using enzymes in this method of medication as it causes a lot of bleeding. This is a concern for many biologists and new enzymes are being produced currently to try and overcome this problem. In conclusion, it is obvious that enzymes have a wide range of uses within industry, analysis, diagnosis and disease treatment. The unique properties of enzymes allowing them to carry out reactions at lower temperatures suitable for the human body (which is vital in all the above examples), their high specificity allowing them to locate tiny amounts of a substance in a large mixture quickly, their availability and cheapness and the fact that they are not used up within experiments make them very useful and essential in many of life’s every day processes. Bibliography 1. www.enzymes.co.uk, Enzyme Services & Consultancy, 1999. Sheehan, N & Cole, C J. (accessed 28/01/03) 2. www.aginfonet.com/aglibrary/content/feed_news/feed_notes.html, 2000. (accessed 28/01/03) 3. htttp://.xtramsn.co.nz/health, Microsoft Corporation, 2001. (accessed 28/01/03) 4. www.cc.nih.gov/drd/sp/t-theropy.html, National Institutes of Health, 2002. (accessed 28/01/03) 5. Toole, G and Toole, S. Understanding Biology for Advanced Level (3rd Ed), Stanley Thomas Publishing, 1995. (accessed 28/01/03) 6. Toole, G and Toole, S. Essential AS Biology, Nelson Thornes Ltd, 2002. (accessed 28/01/03) 7. Roberts, M, Reiss, M and Manger, G. Advanced Biology, Nelson Ltd, 2000 (accessed 28/01/03) 8. Biological Sciences Review, Volume 13, No.3, January 2001. ‘Enzymes & Animal Feeds’, Pg 21, Novo Nordish.