So if a reaction is 0th order with respect to some reactant then the rate is independent of that reactant's concentration. For instance, if we have A and A is transformed into B and K is the rate constant and we know that A is zero's order, what that basically means is the exponent will be zero. This will become one. And so the rate law is v is equal to K. And notice that changing A, either increasing or decreasing will not affect the value of V. And some enzyme catalyze reactions inside our body are in fact 0th order. And what that means is by changing the concentration of A that will not affect that rate of the reaction. Now we can also have something known as a pseudo first order reaction.