Biology 1003
Fall Term 2011
Lab Number: 3
Title: Cell Energetics: Enzyme Role in Biological Reactions
Name: Brandon Moore
Student Number: 100819124
Lab day and time: Wednesday pm
Date: Wednesday November 23, 2011
Introduction
Enzymes are a key aspect in our everyday life and are a key to sustaining life. They are biological catalysts that help speed up the rate of reactions. They do this by lowering the activation energy of chemical reactions (Biology Department, 2011).
In chemical reactions bonds must be broken and new bonds must be formed. In order for this to occur the bonds must be made less stable. For bonds to become less stable a small input of energy is required and this is called the activation energy. In simpler terms, in order for a reaction to begin and proceed spontaneously a small input energy is required to give the reaction a push and get it started (Cooper, 2000).
As said before catalysts are chemical agents used to speed up the rates of reactions. The biological catalyst is a group of proteins called enzymes. Enzymes work by lowering the activation energy and making it easier for the reactants to obtain the necessary energy to break the kinetic barrier. Even though enzymes speed up the rate of reaction, they do not change the free energy of the reactants and the products (Russel et al., 2010).
Enzymes work by combining with reacting molecules at the active site. Each enzyme is specific to only one kind of molecule and can only bind to its specific molecule. The active site is a groove in the enzyme where the molecule will bind to; this is formed by the enzyme folding into a specific shape. When the enzyme is done and the molecules are then in the transitional state, which means the bonds are unstable and ready to be broken, the enzyme remains unchanged and can continue to bind to other molecules (Russel et al., 2010).
Enzymes induce the transition state by three major mechanisms. The
References: Russell, P.J., S.L. Wolfe, P.E. Hertz, C. Starr, M.B. Fenton, H. Addy, D. Maxwell, T. Haffie, and K. Davey. 2010. Biology: Exploring the Diversity of life, first Canadian edition. Nelson Education Ltd., Toronto. Biology Department. 2011. Introductory Biology: BIOL 1003 Lab Manual. Carleton University Press, Ottawa. Worthington Biochemical Corporation. 1972. Introduction to Enzymes. http://www.worthington-biochem.com/introbiochem/effectspH.html. November 22, 2011. Geoffrey M Cooper. 2000. The Cell: A Molecular Approach, Second Edition. Sinauer Associates Inc, Boston University.