AN INVESTIGATION INTO THE EFFECTS OF HEAVY METAL IONS (LEAD ION AND Coursework

AN INVESTIGATION INTO THE EFFECTS OF HEAVY METAL IONS (LEAD ION AND MERCURY ION) ON THE ACTION OT TRYPSIN ENZYME - Coursework Example The above observation will get into the discussion in association with the dissociation of Mercury Nitrate and the lead Nitrate. The above observations might also be explained in terms some complex reactions which do involving the enzyme trypsin and metal ions. RESEARCH AND RATIONAL Enzymes are biological catalyst made up of proteins, they speed up the rate of chemical reactions by lowering the activation energy hence providing an alternative pathway (fig.1). Enzymes remain unchanged at the end of a reaction. They are classified as globular proteins, they are made up of polypeptide chains which coil and or fold up to give a 3D structure which determines the shape of the enzyme and hence, the shape of the active site. http://tfscientist.hubpages.com/hub/what-are-enzymes-where-do-they-work Figure 1http://www.biologyguide.net/unit1/2_enzymes.htm All enzymes have an active site, in 1814 Emil Fischer proposed the lock and key model. According to this theory, the substrate fits perfe ctly into the enzymes active site hence forming an enzyme substrate complex, causing the bonds in the substrate to change. This will eventually lead to the formation of products. The products are released from the enzyme active site leaving the enzyme free to accept another substrate. http://www.elmhurst.edu/~chm/vchembook/571lockkey.html The diagram below illustrates this theory. Figure 2: http://en.wikipedia.org/wiki/File:Competitive_inhibition.svg However X-ray crystallography and computer assisted modelling, research has shown that the lock and key model is not accurate. This has led to the introduction of the ‘induced-fit theory’. It assumes that the substrate influences the final shape of the enzyme active site and that the active site is malleable. Only specific substrates will be able to alter the active site slightly in order for a reaction to take place [1].The diagram below illustrates the induced fit theory. Figure 3: http://www.biologyguide.net/unit1/2_ enzymes.htm There are various factors that influence the activity of enzymes, these include; pH, temperature and Inhibitors. Inhibitors are substances that affect the activity of enzyme, if the site which active of the enzyme gets occupied by a substance which is not a substrate, the activity of the enzyme will decrease because the substrate cannot bind to the active site. This means that both the substrate and the molecule are competing for space on the active site. This is known as a competitive inhibition and can be reversed by the addition of more substrate.  Non-competitive inhibition is another form of inhibition where a molecule binds to the allosteric site on an enzyme hence changing the shape of the active site. This prevents the substrate from binding to the active point. Usually this type is reversible but cannot be overcome by increasing substrate concentration. Trypsin is a serine protease found in the human digestive system, it is essential for the hydrolysis of pro tean such as casein found in milk http://www.princeton.edu/~achaney/tmve/wiki100k/docs/Trypsin.html. Without trypsin, it would be difficult for the human body to absorbed protein; Pb (NO3 )2 and Hg (NO3 )2 contain Pb2+ and Hg2+ ions respectively. These meal ions acts as non-competitive inhibitors and this means that there will be fewer successful