This module will focus on the role of cholesterol in the human body.
In recent years, the harmful role of cholesterol in the body has been widely
publicized. However, cholesterol also has many useful functions in the
body including its role in membrane structure, brain tissue, fetal development
and the biosynthesis of other steroidal hormones. It is a subject that
is intimately connected to the human body. Since many of the students we
teach are ultimately interested in life science careers, I believe this
topic will be of great interest to them. It also gives them a chance to
better understand a subject that is discussed widely in the media and to
give them a more in depth, scientific understanding of it.
We will begin by learning the structure of cholesterol, including its three-dimensional
shape. In order to understand this fairly complicated molecule, we will
begin by learning the structure of the carbon atom itself which should introduce
the students to Lewis Structures as well as hybridization. Next we will
have to examine the effect of putting so many carbon atoms together in a
polycyclic system. Is the molecule rigid? Are there various conformations
of the molecule and what would t heir relative energies be? This will allow
us to explore conformational analysis in both acyclic and cyclic carbon
systems. One can introduce thermochemistry, kinetics and free energy diagrams
through this topic as well.
Finally we can extend this study to other steroids. A variety of other
functional groups can be introduced in this way and the students will be
able to gain a basic understanding of how functionality affects structure,
as well as reactivity. Stereochemistry will also be taught at this point.
In summary, the chemical principles that would be dealt with in this module
include: Hybridization, shapes, isomers, polarity and stereochemistry);
Conformational Analysis (acyclic compounds and cyclohexanes); and Introduction
to Functional Groups.
Our pedagogical approach will be to have students construct their own understanding
of the structure of cholesterol through discovery, in consultation with
a standard organic textbook. This will be done through guided and open-ended
in-class and out-of class activities. Both model kits and computer modeling
will be used to understand the three-dimensional shape of cholesterol.
Students might be assigned group projects in which their task would be to
explain some function of cholesterol in the body, to introduce the class
to a new functional group, or to summarize the activity of a different steroid
in the body. The laboratory could involve such activities as isolating
cholesterol, computer modeling, as well as other experiments that allow
for the student to be involved in both experimental design and data analysis.
In summary, the module will be derived from student-guided learning, involving
significant amounts of communication skills, both oral and written.
Assessment of what the student has learned will include both individual
and group examinations. It will most likely also include oral presentations,
a poster presentation, work on daily assignments and skill in the laboratory.
Tool Kit
Chemical Principles:
Structure and Bonding in Organic Molecules (lewis dot structures, hybridization, shapes, isomers, polarity and stereochemistry)
Conformational Analysis (cyclohexanes)
Introduction to Functional Groups
Thinking Like A Scientist:
Laboratory Procedures (purification and synthesis)
Experimental Design (decision making and safety issues)
Accessing Information (computer/library searching, using reference books, evaluating the reliability of information)
Critical Thinking (recognizing trends, deduction, inference, independent and collaborative learning)
Communication (oral, written, visual, teamwork, lab notebook)
Audience: First semester organic students
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holesterol