What are the properties of water?

This is part of the chemistry of life chapter.

Its important to Biology because :

Water is the medium of life and biology is the study of life.

Water molecules are polar. this means the molecule is charged One end of the molecule is positively charged the other is negatively charged. strong hydrogen bonds that are hard to break form between the negative end of one water molecule and  the positive of another molecule (because negative and positive charges attract each other).

Hydrogen bonds are the key to understand almost all other properties of water. Essentially you cna imagine them as a strong electric glue between water molecules. 

Due to this electric glue water is a.) cohesive this means that the glue holds the molecules together to create a surface tension. 

Water is also adhesive meaning water sticks together when one molecule moves many will move with it (you can imagine this like pulling up on magnet and other magnet sticking to it.

The hydrogen bonds also explain the thermal properties: the temperature of water is extremly stable. This is because hydrogen bonds need to be broken to change the kinetic energy ( warmth is created my moving molecules = kinetic energy but molecules cant move freely if they are electrically glued together) 

because of the negative and positive ends on the hydrogen molecule it can also form bonds with other negative or positive molecule and is therefore an excellent solvent. 

Summary: hydrogen bonds facilitate cohesive adhesive thermal and solvent properties of water.

But why are these important?

cohesive and adhesive properties are important for photosynthesis

thermal properties are important for stabilizing temperature on earth as well as acting as a coolant for humans (sweat).

becuase of excellent solvent properties water is excellent to transport other molecules through the body. (E.g oxygen and amino acids.)