Enzyme :: essays research papers

The plot of enzyme activity Vs. pH is often "bell influence" since twain variant amino acid groups of the enzyme are being tit calculated to different states of ionization at the different pH determine. This means that only superstar of the two possible ionization states of the amino acid place mountain range is effective in enzyme catalysis - in other words, if an acidic side chain like Glu is involved in catalysis, it probably only whole works when it is ionized since Glu side chain carboxylic acid groups have a pK around pH 5, at pH values below this pK, the enzyme go away be slight active while at pH values above the pK, the enzyme will be most active. At higher pH values, another group, for example, the amino side chain group in a Lys may control the activity. So at pH values below the pK of the Lys amino side chain, which is about pH 9, the enzyme is active, while at pH values above the Lys side chain pK, the enzyme will be less active. In the end, the pH op timum lies somewhere between the pK values for these two groups that control the enzymes activity.B. Temperature OptimumMost enzymes have an optimum temperature, which may be related to the type of organism from which the enzyme was isolated. Some organisms like plants grow sanitary sound room temperature and so their enzymes are most active at a temperature around 30 to 40C. A general design of thumb from chemistry is that a reactions rate approximately doubles with a 10C increase in reaction or tick temperature. However, since enzyme are held together by weak non-covalent bonds, at higher temperatures, the enzyme catalyzed rate slows down rather than increases Of courese, at low temperatures, all the molecules in the resolve slow down and so does the enzyme catalyzed reaction. At high temperatures, the thermal move of the molecules become to great for the enzyme to hold its shape or conformation and so it begins to denature and lose its activity. Animal enzymes often have te mperature optima near 37C (especially humans since this is body temperature). For thermophilic organisms, like bacteria or blue-green algae which grow well in near boiling hot springs, frequently higher temperature optima are found some enzymes even have temperature optima near 90C.In the end, the temperature you use for an enzyme assay may depend on the equipment available to you in the lab.