Why is Water so Important to Life?   Water can interact with many other molecules. Why? It is a polar molecule. (One end is slightly positive, one end slightly negative)

The positive end of water bonds to negative ends of other substances. Water’s polarity makes it a great solvent. It dissolves many substances. The positive end of water bonds to negative ends of other substances.   The negative end of water bonds to positive ends of other substances.

See page 51....Water dissolving table salt (Na+Cl-)   Which part of the water molecule will bond to.... The sodium? A:______________ The chlorine? A:_______________ Draw an illustration of this process in your notes.

Water’s bonding/dissolving ability makes it important to life because:   Water can dissolve organic substances such as protein, sugars, and salts. -This makes it easier for cells to break down the substances (protein, sugars, fats) to release the energy. -This also allows cells to gain easier access to electrolytes (salts) that are used for other life functions. (example: nervous system....electrical transmissions)

Water Forms and Unusual Solid -See graph : Water is most dense water is 4o C Frozen water floats because of air trapped in crystal structure.   It insulates the rest of the water and delays freezing of the water underneath the ice.