It has some rather interesting and unusual physical properties compared to other molecules of similar size and composition. This is due in large part to water's ability to form a large number of hydrogen bonds with itself. The structures of biological macromolecules is determined in large part by noncovalent interactions .
Water dramatically influences noncovalent interactions.
Introduction Water is the most abundant substance in living systems. Consequently, all aspects of a cell's function are necessarily influenced by the physical and chemical properties of water. The unusual properties of water are due to hydrogen bonding. This indicates a strong cohesive force exists between water molecules, which does not exist between these other molecules. Water molecules are polar.