Now, the majority of the different types of biological reactions that exist in nature for example, in our body and inside the cells of our body, they exist in water. So water is the natural solvent. It's the solvent that allows all these different types of biological reactions to actually take place in the first place. And because of the properties of water, as we'll see, in just a moment we'll see what these properties are. The fact that water is a solvent allows those reactions to follow a certain pathway. And water also actually helps determine what the final structure is of these biological molecules.