Chemistry of Life: Water A follow-up lecture to Biochemistry notes (also important to the “chemistry of life”)

Refresh: Atoms - basic unit of matter Element-made of atoms Compound - two or more atoms chemically combined What would water be? What is the formula?

Water - essential to life: A. Properties: Polar - uneven distribution of electrons between hydrogen and oxygen (-) near oxygen (+) near hydrogen

Polarity allows water the ability to dissolve many substances (known as the universal solvent) Solution - a solute dissolved in a solvent

2. Hydrogen bonds - gives water many special properties cohesion: attraction of water molecules to each other (Why spiders can walk on a pond’s surface)

Adhesion - attraction between water and other substances Allows water to move from soil up through stems and leaves

B. Other uses of water to living things: -regulates body temperature -maintains cell turgidity -used to maintain shape of proteins -transports nutrients -provides environment for chemical reactions (most important for cells)

Parts of the body vs. % water

Now, time for a quiz…