Denaturation of proteins: Enzymes

A catalyst or a chemical produced by cells to generally speed up specific chemical reaction without changing the chemical reaction at the end of the reaction . Any of various proteins, as pepsin, originating from living cells and capable of producing certain chemical changes in organic substances by catalytic action, as in digestion. Supplement Natural proteins produced in tiny quantities by all living organisms (bacteria, plants, and animals) and functioning as highly selective biochemical catalysts in converting one molecule into another. Enzymes are essential to life because they speed up metabolic reactions to a very great extent, but do not undergo any change in themselves. In the industry they are used for degrading oil spills and wastes into harmless compounds, in cleaning fat (food) stains, and in fermentation processes to make alcoholic beverages. Enzymes are very sensitive to environmental conditions and function best only within a narrow range of temperature and acidity (pH) levels.

Enzymes are usually classified and named according to the reaction they catalyze. The International Union of Biochemistry and Molecular Biology have developed a nomenclature for enzymes, the EC numbers. They are as follows:

  • EC 1 Oxidoreductases: catalyze oxidation/reduction reactions
  • EC 2 Transferases: transfer a functional group
  • EC 3 Hydrolases: catalyze the hydrolysis of various bonds
  • EC 4 Lyases: cleave various bonds by means other than hydrolysis and oxidation
  • EC 5 Isomerases: catalyze isomerization changes within a single molecule
  • EC 6 Ligases: join two molecules with covalent bonds
  • The word enzyme was coined by a German physiologist in the late 1800's to name a digestive process that scientists had been observing. The word was later given to the actual agents discovered to spark the reactions, taken from the Greek √©nzymos, which meant "leavened."

    Types of enzymes

    The enzymes are proteins and they make a biochemical reaction more likely to proceed by lowering the activation energy of the reaction. The Biological catalysts are called enzymes. Based on the type of reactions that the enzymes catalyze, the enzymes are classified into following categories:






    ligases and


    The Oxidoreductases, transferases and hydrolases are the most abundant forms of enzymes.

    Factors contribute to enzyme catalysis

    There are following factors affect the rate at which enzymatic reactions proceed:



    enzyme concentration,

    substrate concentration and

    the presence of any inhibitors or activators.

    Functions of enzymes

    Enzymes catalyze the chemical reactions which are involved in growth, blood coagulation, healing, diseases, breathing, digestion, reproduction and other biological activities. According to biological aspects enzymes are instrumental substances to many functions in living organisms.

    Properties of enzyme

    Catalytic Property.


    Sensitiveness to Heat/Temperature.

    Specific to Hydrogen Ion Concentration (pH)