So all of these macromolecules contain a carbon component. So let's move on to lipids. Now, lipids are also known as fats. And unlike our carbohydrates and proteins, which are water soluble, so that means they are polar and which are polymers. So that means they consist of individual repeating units. Our lipids are not water soluble, so that means they do not dissolve in water they do not dissolve in a polar solvent.