Which component is required for the activation of some enzymes?

a) presence of a co-factor
b) basic ph levels in the substrate
c) higher enzyme concentration
d) lower temperature in the substrate

The correct answer is option A.

Presence of a co-factor is required for the activation of some enzymes. Co-factors are generally metal ions or small molecules (non-protein).Co-factors helps enzymes bind substrate tightly.  For example, NAD⁺/NADH is a co-factor which is required for the activation of the enzyme dehydrogenase. NAD⁺ is the oxidized form and NADH is the reduced form.