Write the biological importance of Ca⁺² and Mg⁺²?

i) Enzymes use ATP in phosphate transfer require ‘Mg’ as the co-factor.
ii) Chlorophyll contains ‘Mg’ useful for photosynthesis.
iii) Bones and teeth contains the major component of ‘Ca’.
iv) ‘Ca⁺²’ plays important role in neuro muscular function, interneuronal transmission and blood coagulation.