Factors Affecting the Activity of Enzymes

Certain factors affect the activity of enzymes including temperature, pH and poisons. Rise in temperature causes rise in enzyme activaty. But at very high temperature denaturation of apoprotein results in the inactivation of enzyme due to the breaking of its hydrogen bonds present in enzyme. Change in pH causes changes in ionic state of a substrate results in the formation of charged particles which may not correspond with the ionic groups present in the active sites of enzymes. As a result no enzyme-substrate complex formed. Certain poison or inhibitors mask the active sites of enzymes forming the enzyme-inhibitor complex. In this situation substrate have to compete for its active site so it is called "competitive inhibition".It can be removed by increasing the concentration of substrate. The conformational change in the enzyme due to the formation of enzyme-inhibitor complex is called "allosteric effect".

Enzyme nomenclature follows some rules. Some enzymes are named after the name of their substrate by adding a suffix 'ase'. For example lipase reacts with lipids (fats), Carbohydrase reacts with carbohydrates and proteinase reacts with proteins. Sometime the name of enzyme refers to the reaction rather than the substrate e.g decarboxylase, dehydrogenase, mutase and oxidase etc. In this case the name of substrate is added to the name of enzyme such as pyruvic acid decarboxylase, succinic acid dehydrogenase, glucomutase and cytochrome oxidase. Old names of enzymes formulated before the nomenclature have been retained.