Lesson Block A:  Essential Chemistry for Biologists

The first chapters in biology text books generally cover the basics of physical (inorganic) and organic chemistry.  It is said that life is based on the cell.  Looking a little deeper we see that cells are composed of molecular structures including organelles such as the nucleus, membrane, and mitochondria.  These in turn are composed of the four types of organic compounds- proteins, carbohydrates, nucleic acids, and lipids.  Many other chemicals are in the watery mixture inside the cell known as the cytosol (cell solution)  

      The sum of  interactions of all of these chemicals and structures  with each other inside the cell and with the outside chemical environment, is what makes the cell alive.  The cell responds to internal and external chemical and physical (such as light) signals to acquire nutrients, avoid predators or pathogens, maintain a constant internal environment (homeostasis) and reproduce.  Clearly, to understand biology a sufficient understanding of chemistry is necessary.  Topics in physics are also needed to a lesser degree.

      There are so many examples that could be offered in support of the last statements above, but here are a few that will serve to make the point and may be found interesting:  Human Nutrition, Digestion, and Absorption; Devil's Gardens in the Amazon Rainforest; Serpentine Plant Communities; Vitamin D Production from Cholestero with Sunlight; Thyroid Normal Function and Disorder; Blood pH, Iron, and Oxygen; and Photosynthesis in Everything from Bacteria to Sequoia Trees.          (development of these topics is upcoming)