Enzymes are proteins, though highly complex and diverse, they serve one basic function; to work as an organic catalyst. A catalyst, as defined by Merriam-Webster dictionary, is a substance that enables a chemical reaction to proceed at a usually faster rate ("Catalyst-Definition and more."). They function by reducing the activation energy, or energy required to start a reaction. The way enzymatic reaction works cannot be altered, but the rate may be changed. Usually, the effect is to reduce the rate, and this is called inhibition, but sometimes the rate of enzyme reaction is raised, and this is called activation (Saboury, A. A.). The enzymes’ shape is the key to its function, and this is how it acts upon the substance, or substrate, lowering the activation energy (Reece and Campbell). Because enzymes are so specific in their shape, they will only work on substrates that fit, and no others.
In this lab we utilized Catechol Oxidase as our enzyme, and Catechol as our substrate. When exposed to oxygen catechol gradually changes to benzoquinone, catechol oxidase speeds up this reaction. We tested the effects of temperature, pH, and inhibitors on this enzyme system. This was all accurately timed and measured to ensure proper results. My hypothesis is that the reaction rates will differ substantially in different temperatures and pH concentrations. I predict the warmer the surrounds in which the reaction is in, the faster the reaction will go. I also predict that a strong acidic or basic solution will slow down or prevent the reaction.
Materials and Methods
On February 12th 2013, at 2pm we began our experiments. We first had to create and extract the catechol oxidase from potatoes, which we did by blending whole potatoes and DI water in a blender for approximately 30 seconds. Once the puree was made, we immediately put it on ice, in an attempt to slow down the conversion to benzoquinone.
To test the
Cited: Reece, Jane, and Neil Campbell. Campbell Biology. 9th ed. Pearson Education Inc., 2011. Chapt 2. Print. Siegbahn, Per E. M. "The Catalytic Cycle Of Catechol Oxidase." Journal Of Biological Inorganic Chemistry 9.5 (2004): 577-590. Academic Search Complete. Web. 24 Feb. 2013. Saboury, A. A. "Enzyme Inhibition And Activation: A General Theory." Journal Of The Iranian Chemical Society 6.2 (2009): 219-229. Academic Search Complete. Web. 24 Feb. 2013. "Catalyst-Definition and more." Springfield: 2013. <http://www.merriam-webster.com/dictionary/catalyst>. "PubChem: Catechol - Compound Summary." Rockville Pike: <http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=289>.