So, carbon is ideal for sharing electrons - forming covalent bonds. There is a continuous range between pure ionic bonds and pure covalent bonds. In vacuum and in water, a covalent bond is strong - 90 kcal or so. Ionic bonds are weakened in water because of shielding by polar water molecules. To understand this, lets look at water in detail.
Water is a polar molecule.
The hydrogen atoms take on a slight positive charge and the oxygen atom takes on a slight negative charge due to unequal sharing of electrons. Water forms Hydrogen bonds between adjacent molecules, giving some stability to liquid water. Water forms Hydrogen bonds to polar groups on proteins, lipids, and carbohydrates and to ions in solution. Hydrophilic substances are those which dissolve in water, forming hydrogen bonds with water molecules Hydrophobic substances are those which don't dissolve in water, often because the hydrocarbon groups have no electronegative atoms to create polarity of electrical charge. We'll discuss why Ammonia would not be a good choice for a biological solvent.