“A Fifty Minutes News Special: Nerve Gas”
Objective(s):
- To understand the interaction of a chemical substance with biological targets such as enzymes
- To understand how one compound has multiple actions throughout the body
- To understand the basic structure of the circulatory and nervous systems
Science Concepts:
Several areas of science are integrated into this activity. Concepts include 1) the behavior of a gas with a high vapor pressure in air and in the bloodstream, 2) the routes of entry of the gas into the body by absorption and inhalation, 3) the ability of the gas to get into the brain, 4) the covalent bonding of the nerve gas to an enzyme to irreversibly inhibit it, 5) the organization of the nervous system, the importance of the neurotransmitter acetylcholine, 6) the distribution of acetylcholine receptors as a basis for the production of multiple effects of nerve gas, and 7) the basis for antidotal therapy by other compounds.
Materials needed:
Video camera (optional)
Procedure:
This activity involves a presentation by the class in a “60 Minutes” television format. Divide the class into 4 groups. Each group is assigned a topic relating to nerve gas and its effects on the body.
Group 1: The history of nerve gas in warfare. The chemical properties of nerve gas.
Group 2: How nerve gas gets into the body and moves around to its targets (discuss absorption and distribution via the circulatory system, including crossing the blood brain barrier)
Group 3: How nerve gas produces its numerous effects on the body (discuss the nervous system, acetylcholine neurotransmission and role of the enzyme acetylcholinesterase)
Group 4: Why the effects of nerve gas are so difficult to reverse (discuss the chemical nature of the nerve gas-acetylcholinesterase bond and what kinds of antidotes are available)
Each group should research their topic prior to the presentation to the class. The presentation should be in the form of a “60 Mintues” show. For example, one of the students in the group could be the interviewer and the other students in the group could be various types of interviewees such as: an historian, chemist, military officer, neurologist, neuroscientist, pharmacologist, etc.. The interview should reveal all the necessary information associated with the group’s topic. Encourage the students to include visual aids like posters to show some of the scientific principles. If a video camera is available, it should be used and copies of the tapes can be made for each of the students to keep.
Assessment strategies:
Have the students write “letters to the editor” asking specific questions about nerve gas and its effects on the body. They can hand in the questions at the end of the presentation. In the following weeks, read aloud 1 question at the end of a class period and invite an answer from the class. Keep track of number of right answers over the several weeks and then provide the class with a final printout of the results.
