Unit 3 – The Chemistry of Water 1
Objective 1 – Specify the chemical and physical properties of water.
Major component in the body
Inorganic compound made up of one oxygen and two hydrogen molecules
Held together by a single covalent bond
The slight negative and slight positive charge
makes water a polar molecule
Objective 2 – Explain the biological importance of water.
a. The most abundant of all substances in the body. It is found in most tissues such as 60% of RBC’s, 75% of
muscles, and 92% of blood plasma.
b. Universal solvent and suspending material; materials necessary for health and survival of the body are
dissolved in water. They travel, dissolved in the blood plasma, through the circulatory system, and diffuse,
dissolved in water, through the tissue fluid and into and out of cells. Many organic molecules (i.e., amino
acids and glucose) dissolve in water, and many other inorganic molecules such as salts.
c. It acts as a raw material in many chemical reactions. It is used in the process of digestion to break down
large nutrient molecules into their smaller components (i.e., the breakdown of larger carbohydrates into
monosaccharides). Water molecules are also used in production of hormones and enzymes.
d. Used in maintaining and regulating body temperature. Water has a very high specific heat: relative to
many other substances, water requires much more heat to raise its temperature and must lose a lot of
heat to lower its temperature. This allows water to act as a good storage medium for heat in the body. If
the temperature in the external environment is too high, the eva