Calcium ions are cofactors for the
enzyme rennin by binding to
either the substrate or enzyme
they make the formation of
enzyme-substrate complex
easier.(affects charge distribution
and the shape of the
enzyme-substrate complex)
So lower concentration of calcium ions will
decrease the rate of the reaction.
While higher concentration of calcium ions
will increase the rate of the reaction
Sodium substrate has to be
added as to remove all the
calcium ions that are normally
present in milk
this than allows as to test the
effect of different
concentrations of calcium
ions.