The environmental factors that effect turnip peroxidase
Four environmental factors of enzymes were tested in lab. The changing of pH, substrate concentrations, temperature, and an inhibitor (NaCl) and the effects it hade on the enzyme turnip peroxidase. Enzymes are biological catalysts which increase reaction rates by lowering the activation energies of substrates. A substrate is a reactant that interacts with the enzyme. The enzyme and substrate can be viewed as the recently discovered "induced fit model", which suggests enzymes are flexible and dynamic things that change their shape so all these substrates (reactants) can become catalyzed when the activation energy is lowered and the reactions happen a lot faster. Sometimes in cells though it may not need a particular substrate (reactant) so an inhibitor comes into play. Inhibitors are basically regulators that inhibit (disallow) the process of catalysis to take place within a particular substrate. There are two types of inhibitors that occur in such reactions. Competitive inhibiters are remarkably similar to the substrate, so much that it can match interchangeably with the substrate, thus leading to a halt in the production of the intended product. Another variety of inhibitor is the allosteric inhibitors. Allosteric inhibitors change the shape of the enzyme by binding to a different site other the active site, which is the usual site for catalysis. Usually the allosteric inhibitors make contact with the side of the enzyme opposite the active site. In some occasions however an allosteric activator is introduced and functions by connecting to the enzyme in a way that it allows for easy access for a substrate to the active site. Allosteric activators are the opposite of allosteric inhibitors. These regulators (both inhibitive and active in function) help keep the cell in homeostasis by not allowing too much or too little of a needed or not needed product to be produced.. Enzyme activity is also regulated by cofactors which are either metal ions (e.g. Zn2+, Mg2+) or
References: 1.Weinheimer, T. White,D. 2003. Using peroxidase to demonstrate enzyme kinetics.The American Biology Teacher:pp116-121. 2.Helser,T 2006. Enzyme catalyzed reactions. Employee.oneonta.edu/helsert/enzyme.html 3.Pitkin,R.B. 1990. Introductory biology manual.Shippensburg university,Shippenburg. PA.