TIGER

Other Resources: 7 results
Molecular Models of Real and Mock Illicit Drugs from a Forensic Chemistry Activity  William F. Coleman
The Featured Molecules for this month come from the paper by Shawn Hasan, Deborah Bromfield-Lee, Maria T. Oliver-Hoyo, and Jose A. Cintron-Maldonado (1). The authors describe a forensic chemistry exercise in which model compounds are used to simulate the behavior of various drugs in a series of chemical tests. Structures of a number of the chemicals used in the experiment, and several of the drugs they are serving as proxy for, have been added to the molecule collection. Other substances used in the experiment are already part of the collection, including caffeine and aspirin. One structure that may be both intriguing and confusing to students is that of chlorpromazine (Thorazine, Figure 1). A majority of students might well expect the ring portion of the molecule to show a planar structure. This is not what is found from calculations at the HF/6311++G(d,p) level in both the gas phase and in water. Instead, the three rings are in a V-like formation with a deformation of approximately 50 degrees from planarity. Tracking down the source of this non-planarity would be a useful computational exercise. Does it arise from the presence of the alkyl chain (steric effect), from the chloro group (electronic effect), or from electronic effects involving the elements of the heterocyclic ring? As a starting point to addressing these questions, students could be introduced to the use of model compounds in computation. One such compound would be the parent ring system phenothiazine (Figure 2). That molecule contains neither a chloro substituent nor an extended alkyl group. Is it also found to be non-planar? Is the deformation angle the same, larger, or smaller than in chlorpromazine? Does the addition of chloro group to phenothiazene change the angle significantly? What about the addition of an alkyl group? If the model compound is forced to be planar are all of the vibrational frequencies real (positive)? If not, what type of deformation is suggested by the imaginary (negative) vibration?
Drugs / Pharmaceuticals |
Forensic Chemistry
Enzyme Activity as a Function of pH  Paul Krause
A matched pair of documents providing an introduction to the role of pH in the regulation of enzyme activity. The tutorial document contains all the equations and graphs for students to use to study the role of pH in enzyme kinetics. In the EnzymeExercise twin document all quations are omitted so that students can develop these interactively. The Exercise document is also ideal for display during lecture where the ideas can be developed interactively with the class as a whole.
Enzymes
Catalysis in Biology  Tim Wendorff
A section of ChemPrime, the Chemical Educations Digital Library's free General Chemistry textbook.
Catalysis |
Enzymes
ChemPaths 104 M Feb 28  John W. Moore
Today in Chem 104: * Lecture: Catalysis * Reading: Kotz, Ch. 15, Sec. 6 Moore, Ch. 13, Sec. 8-10 * Homework #6 due by 11:55 pm F Mar 4 * Biomolecules Tutorial: Enzymes (and Enzymes Quiz) due at 11:55 pm, W Mar 2.
Catalysis |
Enzymes
Increasing the Rate of a Reaction  Ed Vitz, John W. Moore
A section of ChemPrime, the Chemical Educations Digital Library's free General Chemistry textbook.
Catalysis |
Enzymes
Proteins  Ed Vitz, John W. Moore
A section of ChemPrime, the Chemical Educations Digital Library's free General Chemistry textbook.
Proteins / Peptides |
Enzymes
Netorials  
The Netorials cover selected topics in first-year chemistry including: Chemical Reactions, Stoichiometry, Intermolecular Forces, Acids & Bases, Biomolecules, and Electrochemistry.
Acids / Bases |
Stoichiometry |
Proteins / Peptides |
Enzymes |
Carbohydrates |
Nucleic Acids / DNA / RNA |
Lipids |
Oxidation / Reduction |
Noncovalent Interactions