Hydrolysis of starch for fungal amylase Aspergillus Oryzae and bacterial amylase Bacillus Licheniformis at different temperatures.
PI 4593042 Florida International University
BSC 1010L, section UO9, March 6, 2013
Enzymes are very specific protein because they contain one active site on their surface that enable the substrate to bind to the enzyme and form the enzyme substrate complex and then release the products. The principal function of enzymes is to increase the rate of the chemical reactions. Enzymes have a set of conditions at which they work perfectly; this is known as optimal condition. Fungal and bacterial amylase are the enzymes that we going to study for their ability to break down starch. In order to determine how temperature affects the activity of amylase enzyme and the optimal temperature for fungal and bacterial amylase, the activity of these enzymes were tested at different temperature and times and iodine was used as indicator of presence of starch. During the experiment we observed that bacterial amylase had faster enzymatic activity than fungal amylase; bacterial amylase achieved 100% hydrolysis at 40°c and 60°c at 2 minutes time and fungal amylase achieved partial hydrolysis at 60°c at 4 minutes time. With all of this we can say that the optimal temperature for fungal and bacterial are almost the same, but bacterial have faster amylase activity than fungal and that is possible because bacterial amylase is found in human saliva, were digesting process begins.
Life is regulated by chemical reactions, but these reactions would take too long to occur without presence of specific proteins that catalyze all biological processes in living organisms transforming one molecule into another, this catalysts are called enzymes (Copeland, Robert 2000). Enzymes are very specific proteins because they contain one active site on their surface that enables the substrate to bind to the enzyme and form the enzyme substrate complex and then release the products. (Figure 1).Because enzymes are so specific, one enzyme catalyzes just one reaction, that is why thousands of different enzymes exist in a cell catalyzing thousands of different chemical reactions.
All enzymes work together in catabolic (breakdown or digestion of large, complex molecules) and anabolic process (synthesis of large molecules) (Copeland, Robert 2000).The chemical breakdowns of nutrients by digestive enzymes are what make possible the mechanical breakdown of food (Fried& Handemenos,2001).That is one of the things that make enzymes very important in our life and demonstrate that the main function of enzymes is to increase the rate of the reaction without altering its equilibrium (Fried& Handemenos,2003). All enzymes have different conditions at which they work bets, these numbers of conditions are called optimal conditions and these often are the same as the organism habitat conditions. But enzymatic activity is not as easy as it looks because different factors can affect the rate of the reaction, examples are the PH, substrate concentration, salt concentration, inhibitor, activators and temperature (Alberte , Pitzer & Calero, 2012).But how can temperature affect the rate of enzymatic activity? If temperature increase, the rate of chemical reaction increase, but if this temperature increase drastically beyond specific temperature (optimal) the rate of the reaction is reduce because enzymes are protein and at temperatures too high they denature (lose shape), and in this way the substrate is unavailable to bind with the active site; on the other hand when temperatures are too low less contact is achieved between enzyme and substrate because the movement of molecules decrease (Alberte , Pitzer & Calero, 2012). Although enzymes make...
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