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Unit 6.7 Chemical Processes
in Biology
Biological systems contain sophisticated molecular structures,
which are involved in millions of reactions. Enzymes regulate
the chemical processes in organisms.
Video program cues: 44:10-57:15
Chemicals in medicine
"The students ought to understand that
if they cut themselves, and put [<3%] hydrogen peroxide
on their hands, they are going to see bubbles. If they leave
it there for too long, it is going to start hurting, and
eventually, if they rinse it off, they will see white stuff.
The bubbles are oxygen coming from the hydrogen peroxide.
This occurs because metal ions in the body fluid, mainly
iron, catalytically decompose the hydrogen peroxide in a
process that is called Fenton chemistry. It produces the
hydroxyl radical, which is a vicious reagent. It will attack
virtually all organic compounds and cause them to decompose.
If you cut yourself, it’s a very good reagent because
it sterilizes the place due to its very reactive nature."
Dr. Terry
Collins
Professor of Chemistry, Carnegie Mellon University
Links
- From HowStuffWorks,
an explanation of why peroxide bubbles on a cut.
Reading
Stinson, S., (2001)' Iron-Catalyzed Olefin Oxidation, 'Chemical
& Engineering New, Vol. 79, No. 30, pp. 9.
Hydrogen peroxide decomposition laboratory
Leslie Pierce teaches about the rate of decomposition of
Hydrogen Peroxide by the catalase enzyme.
Activity
Link
Readings
Ragsdale, R.O.; Vanderhooft , J. C.; Zipp, A. P. (1998)'
Small-Scale Kinetic Study of the Catalyzed Decomposition
of Hydrogen Peroxide, 'Journal of Chemical Education,
Vol. 75, No. 2, pp: 215-216.
Marzzacco, C. J. (1999)' The Enthalpy of Decomposition of
Hydrogen Peroxide: A General Chemistry Calorimetry Experiment,
'Journal of Chemical Education, Vol. 76, No. 11,
pp: 1517-1518.
How are we affected by chemistry?
Students’ ideas
"We are affected by chemistry because
basically we are made up of chemicals."
"If I know what the chemical make-up is, I know what
will happen in chemistry. "
"The brain is a big chemical reaction"
The chemistry of the human body
"Our own bodies are extraordinary biological
chemical manufacturing systems, where we use our genes to
make highly complex molecules. Bioscience has made tremendous
advances in the last 10 years, and so in the future you
will see a lot of the chemistry facilitated by bioprocesses.
We have fermentation processes, genetic engineering of growing
things in a field, a combination of the two, combinations
of traditional chemistry, boiling things and adding, introducing
things into plants and microbes in bacteria. We are headed
towards the ability to design highly complex molecules such
as we are. We are a mass of highly sophisticated molecular
structures, billions of years old. And we are trying to
understand ourselves for the first time. And it didn’t
take an extraordinary amount of energy to create these molecules;
we are all very low-energy synthesized beings."
Dr. Richard Wool
Professor of Chemical Engineerings, University of Delaware
Link
Reading
Thayer, A.M. (2001) Biocatalysis, 'Chemical & Engineering
News, Vol. 79, No. 21, pp. 27-34.
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