Types of essential elementExamplesStructural elementsCarbon, oxygen, hydrogen and nitrogen Elements as component Magnesium in chlorophyll, of energyphosphorus in ATP Activator or inhibitorMagnesium, zinc, calcium, of enzymes potassium and molybdenumElements altering the Potassium regulates the openingosmotic potential of cell and closing of stomataEssential elementEnzyme activatedMagnesiumRibulose bisphosphate carboxylase oxygenase and phosphoenolpyruvate carboxylase involved in carbon dioxide fixation.ZincAlcohol dehydrogenase, CalciumSeveral key enzymes like pancreatic lipase, acid phosphatase, cholinesterase, ATPases, and succinic, dehydrogenase, PotassiumAdenosine triphosphate (ATP) synthase enzymeMolybdenum Nitrogenase enzyme involved in nitrogen fixationEssential elementEnzyme inhibitedMagnesiumEssential for base excision repair enzymes but inhibits substrate binding of N-methylpurine -DNA glycosylase.