What advantages do covalent compounds have over ionic compounds for living organisms?

Answer 1

Covalent compounds can be made into an almost limitless variety of compounds by using only a very few building blocks (just four for the most basic of amino acids C carbon, H hydrogen, N nitrogen and O oxygen).

Also covalent compound have a physical flexibility that ionic compounds lack, for example the amount of flex that a crystal of salt can take is minuscule compared to the flex that a long protein chain can take. This is evidenced by the fact that DNA is twisted around itself then rolled up and finally twisted again to form the distinctive X shape of the chromosome.

Finally covalent compound are not readily soluble in water meaning that although we drink water we are not taken along with it when we visit the toilet. There are probably hundreds more. Hope this helps.

Answer 2

For one thing, they don't dissolve so readily in water...