Some Concepts for Consideration:
Comprehend

In chemistry we attempt to use the behavior

we see of materials to postulate microscopic phenomena at the atomic and molecular scale. 

For example, we studied the properties of liquids. We saw that water boils at a very high temperature for a substance with a molecular weight of 18, thus we postulate that some forces we call hydrogen bonds hold individual water molecules together.

Conversly, we use the information we get at the molecular level to explain what we actually experience.  For example, we looked at the crystal structure of ice as determined by x-ray analysis.   We could calculate that individual water molecules in ice were held far enough apart in the crystal to make the overall density of crystalline ice less than water.  The crystal structure explains why ice floats on water.

In studying chemistry, we are forced to represent both this microscopic realm and our tangible surroundings through imperfect symbols. 

Our representations always lack some precision in expressing reality. 

For example, the symbol H2O as the structure of water gives us the ratio of hydrogen to oxygen, but fails to tell us the oxygen is bonded to each of the hydrogens and the angle of the bonds between the three atoms is 109o.

Warning!  Acid-base chemistry depends upon an understanding of chemical equilibrium.  But our representations of equilibrium are generally flawed by the fact that when we DO anything to a system at equilibrium, we disturb the system and it is no longer in equilibrium.  For example, we will do many calculations in chemistry expressing equilibrium conditions after one or more conditions has changed.  But in most real world systems, true equilibrium conditions are never reached since systems are influenced by ever-changing conditions.

 

ChemCases.Com
Drug Pathways and Chemical Concepts
Prof. Sally Boudinot

We rely on drugs to make us healthy when we are sick and to keep us healthy when we are well.  We can:

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swallow them or

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inject them or

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inhale them.

but the trick is to make these drugs chemically available to our body's systems as they are needed.

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In this ChemCases.com instructional unit on drug pathways and chemical concepts we will:

  1. Look at the chemical concepts underlying chemical equilibrium and acid/base chemistry.

  2. Examine the role of acid/base chemistry, solubility and chemical kinetics in the discovery, development and use and abuse of barbiturates like phenobarbitol.

  3. Lead us through the properties of the GI tract and how they affect drug delivery

  4. Show how critical evaluation of these chemical principles helped us develop and understand the unusual behavior of penicillin.   Lead us to a study of how to handle drug supplies in an epidemic.

 

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© 2000 Kennesaw State University
Principal Investigator
Laurence Peterson; Project Director Matthew Hermes.
Author of this module
Matt Hermes.

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ChemCases.com is a National Science Foundation supported curriculum development project.

Prof. Sally Boudinot
College of Pharmacy
University of Georgia
Athens, GA
sallyb@rx.uga.edu