Enzymes, Characteristics of Enzymes-Biology XI


Enzyme: a substance produced by a living organism which acts as a catalyst to bring about a specific biochemical reaction.

Characteristics of Enzymes:

Pollution & Types of Pollution

  • Enzymes are bio-catalysts.
  • Speed up the chemical reaction.
  • Majority of enzymes are proteins in nature.
  • Enzymes may work inside the cell (endozyme) or may work outside the cell (Exozyme)
  • They are specific in nature
  • Substance on which an enzyme acts in called as substrate.
  • It works as both as acid and as well as base.
  • Enzyme contains a reaction site where a substance gets attached is called as active site.
  • Enzymes are also thermolabile and lose their activity when the temperature rises.(Heat Sensitive)
  • Their activities may be affected by temperature, PH Electra.
  • Enzyme activities can be stopped by inhibitors.
  • Enzymes activities can be accelerated by activities.

Catalyst are those which just help in any reaction without taking part into.

A protein that acts as a catalyst in biochemical reactions. Each enzyme is specific to a particular reactions or group of similar reactions. Many require the association of certain non-protein co-factors in order to function. The molecule undergoing  reaction (the substance) binds to a specific active site on the enzyme molecule to form a short lived intermediate this gently in creases (by a factor of up to 1020) the rate at which the reaction proceeds to form the product. Enzyme activity is influenced the substrate concentration and by temperature and PH, which must lie within a certain range. Other molecules may compete for the active site, causing inhibition of the enzyme or even irreversible destruction of its Catalytic properties.

Enzyme production is governed by a cell’s germs. Enzymes activity is further controlled by PH change, alternations in the concentration of essential co-factors feedback inhibition by the products of the reaction and activation by another enzyme. Either form a less active form or an inactive precursor (zynogen) such changes may themselves by under the control of hormones on the nervous system.

Significant Figures (Chemistry-XI)

The names of most enzymes ends in ase, which is added to the names of the substrates on which they act, thus lactase is the enzyme that acts to break down lactose.