Now, these two properties lead directly into something called the hydrophobic effect. So the hydrophobic effect is a manifestation of these two properties, as we'll see in just a moment. And the hydrophobic effect plays an important role in the field of biochemistry. So let's suppose we take water molecules and we place some type of polar substance into the water molecule. For example, sodium chloride. Now, sodium chloride is polar because it consists of an ionic bond.