What is the major diff. in chem. composition btwn biological compounds that are soluble and those that aren't?

Question

I'm thinking the answer is the polarity is what makes something soluble and then the non-polar make it non-soluble...please help

Answer 1

You are right about the polarity. Polarity just means that there are plus and minus charges on different parts of the molecule. These charged regions are like little handles that other molecules (that are also polar) can get a grip on. Non-polar molecules are like a big smooth surface - nothing to get hold of to rip it apart. Of course when I talk about handles, I talking metaphorically. The surface it self is not necessarily rough for smooth, its just that the charged regions attract the charged regions of other molecules, so its a sort of "handle" in the sense that it is a region of the molecule that can be held onto and pulled on.

Answer 2

WATER soluble/polar compounds tend to contain the following groups:
carboxyls, amines, hydroxyls, plus some others

Water insoluble /non-polar compounds have alkyl chains, or unsubstituted rings, and commonly ester or amide linkages.