Concentration of Reactants in a Zero-Order Reaction

[Noe BM 1J]

Why does increasing the concentration of reactants in a zero-order reaction not affect the reaction rate?

[Kimberly Koo 2I]

Because zero order reactions are equal to the rate constant, k. In different order reactions, the concentrations are put to the power of the reaction's order, and in the case of zero order reactions, the concentration is put to the power of 0, and anything to the power of 0 is equal to one, so the concentration of the reactants doesn't have an affect

[Ashley Wang 4G]

It is simply how a zero-order reaction is defined - the rate is independent of concentration of reactions.
For example, if the reaction requires an enzyme to proceed, but the enzyme is already saturated, increasing the concentration of the reactant does not affect the reaction rate.

Hope this helps!