Wall Water Features

What are the features of water that make it so important to life on earth?

Public Comments

1. Hydrogen and Oxygen
2. The hydrogen atoms are on one end of the molecule, so each molecule is polarized, with a positive and a negative end. That allows it to form hydrogen bonds with other polarized molecules, as well as with ions, which in turn means it acts as a solvent for those substances. Meanwhile, non-polarized molecules such as lipids are repelled by water for the same reason - the water molecules have greater attraction to each other than to such molecules. These properties, combined with water's ability to remain liquid through a wide range of earth-normal temperatures and pressures, means that cellular structures behave in predictable ways in water. Cellular membranes have water-phobic lipid tails that always point away from the water, and water-philic heads that always are nearest the outside of the membrane where the water is. Thus the water causes the membranes to keep their shape. Similarly, different parts of proteins are water-phobic and water-philic, and this causes them to fold so that the water-phobic parts are on the inside of the crumple farthest from the water. Proteins function because they are a particular shape, and they take that shape because of water. Finally, the cytoplasm inside the cell is mostly water, and because it's liquid many molecules can float around in it and interact with each other to carry on the basic processes of life.