Why are enzymes required for cellular metabolic pathways?

single enzyme can convert one substrate into many different products.

a. ezymes are consumed by metabolic pathways when reactants are converted to products.

b. The enzymes that are present in a cell determine which metabolic reactions can occur in the cell.

c. An enzyme increases the rate of a reaction that would otherwise occur too slowly.

d. A cell can regulate metabolic pathways by controlling the enzyme concentration in the cell.