Enzymes are biological catalysts and the activation energy is the minimum amount of energy required by the reactants for the reaction to take place. Enzymes increase the rate of chemical reactions while remaining unchanged, decreasing the activation energy needed for the reaction to proceed. Enzymes are made up of proteins that are folded into complex shapes that allow smaller molecules to fit inside them. These smaller molecules fit into the active site of an enzyme. The active site is where specific substrate molecules bind and the chemical reaction takes place. The chemical structure and bonds between amino acids determine the shape of an active site. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an original essay All metabolic pathways are controlled by enzymes. In metabolic pathways, the substrate is modified at each step to obtain the final product. Almost all metabolic pathways are reversible. Sometimes a specific substrate or enzyme is not available at one point in the pathway, but the final product can still be obtained using an alternative pathway. Two types of metabolic pathways are anabolic and catabolic. Anabolic pathways require energy to transform small molecules into larger molecules. Catabolic pathways produce energy when they break down large molecules into smaller ones. There are many factors that influence enzyme activity. These include: temperature, pH, enzyme concentration, substrate concentration, and presence of inhibitors or activators. Please note: this is just a sample. Get a custom paper from our expert writers now. Get a custom essay An inhibitor decreases the rate of an enzyme controlled reaction. Competitive inhibitors and non-competitive inhibitors are two common types of inhibitors.Competitive inhibitors. Inhibitor molecules bind to the active site to prevent substrate molecules from binding to the active site. The molecular structure of competitive inhibitors is similar to that of the substrate, so it can fit into the active site and block the substrate. Non-competitive inhibitors. The inhibitor reduces the activity of the enzyme and binds equally well to the enzyme regardless of whether it has already bound to the substrate or not. The inhibitor can bind to the enzyme regardless of whether the substrate has already been bound or not, but if it has a higher affinity for binding the enzyme in one state or the other, it is called a mixed inhibitor. Works Cited Berg, J. M., Tymoczko, J. L. , & Gatto, G. J. (2020). Biochemistry (9th ed.). W. H. Freeman and Company. Nelson, D. L., Cox, M. M. (2020). Lehninger Principles of Biochemistry (8th ed.). W. H. Freeman and Company. Lodish, H., Berk, A., Zipursky, S. L., et al. (2022). Molecular Cell Biology (9th ed.). W. H. Freeman and Company. Garrett, R. H., & Grisham, C. M. (2019). Biochemistry (6th ed.). Cengage Learning.Alberts, B., Johnson, A., Lewis, J., et al. (2019). Molecular biology of the cell (6th ed.). Garland Science.Cox, M.M., Nelson, D.L. (2021). Lehninger Principles of Biochemistry: Study Guide and Solutions Manual (7th ed.). W. H. Freeman and Company. Nelson, D. L., Cox, M. M. (2021). Lehninger Principles of Biochemistry: Lecture Notebook (7th ed.). W. H. Freeman and Company.Price, NC, Stevens, L. (2020). Fundamentals of Enzymology: Cellular and Molecular Biology of Catalytic Proteins. Oxford University Press.Cornish-Bowden, A. (2012). Fundamentals of enzyme kinetics (4th ed.). Wiley. Segel, I. H. (1993). Enzyme kinetics: behavior and analysis of rapid equilibrium and steady-state enzyme systems. Wiley.