Even we add some amount of Ca n Mg ions in soft water to make it hard for enzymatic desizing-
what actually hard water do with it r how it increases rate of reaction:
Salts and ions may have many different effects of the activity of an enzyme.For example, inorganic ions may bind to some of the ionic side chains of a protein. This kind of interaction, although not affecting the three dimensional shape of ...the enzyme in a substantial manner could make it easier for a substrate molecule to locate or bind to the active site of the enzyme. Thus the presence of the ion in optimum concentrations could alter the rate of the reaction.
Many enzymes exist in two states, an inactive and an active state.Usually these states differ in the conformation, or three-dimensional shape of the enzyme. The balance between these two states provides a means for regulating the activi...ty of the enzyme, in effect, by turning it on or off.
Often the switch that controls which state the enzyme is in is provided by a small molecule which binds to a receptor site somewhere on the surface of the enzyme. Such a small molecule is called an allosteric effector. For alpha-amylases from mammals, chloride ion is the allosteric effector. These amylases have a binding site for chloride ion, which contains a positively charged amino acid residue (lysine, which at physiological pH is in the ammonium ion form). This positive charge assists binding of the negatively charged chloride ion, and the size of the binding pocket excludes larger negative ions.
Binding of chloride causes a conformational change to the amylase, switching it to the more active state. we use alpha amylase enzymes in desizing.
