All fields of biology are based on methodical experimentation. Therefore, laboratory classes where students perform well-designed experiments using relevant techniques are an essential part of an undergraduate education in biology. Designing experiments that allow the maximum amount of hands-on student participation can be difficult in courses with high enrollment and large numbers of students per laboratory section. Our focus is to come up with laboratory projects for the Biological Sciences undergraduate lab courses that provide the highest educational benefit to the students while still being manageable with the high enrollment numbers here at UCSD. In designing experiments to accomplish this, each of the following must be achieved.
The signal transduction of fibroblast growth factors (FGFs), and how FGF signaling can alter cellular sensitivity to DNA damaging agents and anti-cancer drugs.
This course introduces some of the experimental techniques used in biochemistry and molecular biology and provides hands-on training for working in a biochemistry lab. The laboratory work consists of three projects, each of which focuses on answering a question about a biological system, analyzing the effectiveness of an experimental strategy, or identifying an unknown. Through this the students develop the scientific reasoning skills required to design and interpret the data from scientific experiments.
Example of an experiment from a student project in Biochemical Techniques:
Sea urchins are a well-established model system for studying fertilization and early development. Urchin gametes are also an excellent tool for teaching cell biology in the laboratory, allowing students to make direct connections between biochemical changes in the egg and the cellular events of fertilization that can be observed under the microscope. The cytoplasmic Ca2+ influx that occurs upon sperm binding is a central node in fertilization signal transduction, and it stimulates many of the events of egg activation, including exocytosis of the cortical granules and elevation of the fertilization envelope. In this experiment, the students are posed with the question, is the calcium influx sufficient to produce cell division (first cleavage) after fertilization? To answer this they artificially induce a Ca2+ influx in unfertilized eggs using the calcium ionophore A23187. By observing whether or not unfertilized eggs undergo parthenogenic cleavage following A23187 treatment, the students can determine if the fertilization calcium influx is sufficient for re-entry of the zygote into the cell cycle. The concepts of necessary and sufficient in experimental design and interpretation of results are emphasized to help develop student reasoning skills.
This course examines the concepts of energy and metabolism, and how they are harnessed and regulated at the cellular and molecular level. The action of enzymes is introduced, including the kinetics of enzyme-catalyzed reactions, the chemical mechanisms through which enzymes produce catalysis, and the regulation of catalytic activity. The remainder of the course focuses on metabolism, the various pathways by which biological molecules are broken down to provide energy for the cell, and by which new biological molecules are synthesized. In our study of metabolism we try to highlight how energy flows in the cell, such as in the oxidation of glucose to produce ATP, and how this energy and energy-containing intermediates are utilized to construct new molecules, as in the synthesis of fatty acids from acetyl-CoA. The various biochemical pathways that accomplish this are examined in detail. We also look at how the cell manages the free-energy changes that occur in these metabolic pathways, and how these pathways are regulated so that metabolism occurs in coordinated fashion.