Biological Enzymes PDF

Define enzyme, metabolism, reactant, product, substrate, and denature Describe the specific action of the enzyme catalase, include the substrate and products of the reaction Describe the components of an enzyme Explain oxidation/reduction reactions Determine how factors such as pH, temperature, and...

Define enzyme, metabolism, reactant, product, substrate, and denature Describe the specific action of the enzyme catalase, include the substrate and products of the reaction Describe the components of an enzyme Explain oxidation/reduction reactions Determine how factors such as pH, temperature, and substrate affect enzyme activity Appreciate the importance of enzymes in chemical reactions. TYPES TYPES NOMENCLATURE OF ENZYMES o An enzyme is named according to the name of the substrate it catalyses. o Some enzymes were named before a systematic way of naming enzyme was formed. Example: pepsin, trypsin and rennin o By adding suffix -ase at the end of the name of the substrate, enzymes are named. o Enzyme for catalyzing the hydrolysis is termed as hydrolase. Example : maltose + water maltase glucose + glucose  substrate enzymes products lactose lactase glucose + galactose maltose maltase Glucose cellulose cellulase Glucose lipid lipase Glycerol + fatty acid starch amylase Maltose protein protease Peptides + polypeptide  LOCK AND KEY MODEL  Proposed by EMIL FISCHER in 1894.  Lock and key hypothesis assumes the active site of an enzymes are rigid in its shape.  There is no change in the active site before and after a chemical reaction.  EFFECT OF PH  Rate of almost all enzymes catalyzed reactions depends on pH  Most enzymes exhibit optimal activity at pH value between 5 and 9  High or low pH value than optimum value will cause ionization of enzyme which result in denaturation of enzyme  EFFECT OF TEMPERATURE Raising the temperature increases the rate of enzyme catalyzed reaction by increasing kinetic energy of reacting molecules. Enzymes work maximum over a particular temperature known as optimum temperature. Enzymes for humans generally exhibit stability temperature up to 35-450C. However, some times heat energy can also increase kinetic energy to a point that exceed the energy barrier which results in denaturing of enzymes.