Colorado high school science teachers learn by doing.
Which would you find more engaging: listening to a lecture on the anatomy and physiology of the circulatory system or performing mock heart bypass surgery?
In a Hughes Initiative workshop at the University of Colorado at Boulder, 11 high school science teachers found out first-hand that there's no contest between listening and learning by doing. The teachers dissected cow hearts and then-using straws and plastic tubing-simulated blood flow through the heart and performed bypass surgery.
"I think doing surgery will get kids really excited," said Greg Cocking, a teacher at Centaurus High School in Lafayette, Colo. "I definitely plan to use this lab in my own classroom."
The free summer workshop, based on videotapes of HHMI's Holiday Lectures on Science, is an annual professional development program for teachers supported by a grant from the HHMI's Undergraduate Biological Sciences Education program, the third in a series of awards to UCB totaling $5.6 million.
Hughes Initiative scientists-in-residence Samantha Messier and Kristin Swihart designed the workshop around four lectures on heart disease and hypertension given last December by HHMI Investigators Christine Seidman and Richard Lifton. Easily replicated activities using inexpensive, readily obtainable supplies like straws, salt and food coloring brought each videotaped lecture to life.
"This workshop, emphasizing hands-on, inquiry-based activities appropriate for the classroom, greatly expands the potential of the Holiday Lectures as a resource for teachers," said Julie Graf, UCB Hughes Initiative director.
Lifton's lecture, "Telltale Genes: Charting Human Disease," set the stage for a session on mapping genetic diseases. Using paper cutouts representing the four bases that make up DNA, the teachers assembled DNA molecules-a hands-on introduction to DNA structure and replication. Then they were introduced to more complicated molecular biology techniques such as polymerase chain reaction and DNA sequencing.
During the DNA activities, Joy Kay, a teacher at Thomas Jefferson High School in Denver, couldn't contain her enthusiasm. "This is so cool!" she exclaimed. "Now I really understand how it works.
After viewing Seidman's lecture about the mutations underlying hypertrophic cardiomyopathy-a heart disorder that can cause sudden death-the teachers donned colored T-shirts representing the different proteins involved in normal muscle contraction: turquoise for myosin, black for actin, red for tropomyosin, white for troponin. They arranged themselves as the proteins in muscle fiber do: lines of myosin facing lines of actin, tropomyosin and troponin. When the "muscle" received a calcium signal to contract, the red and white-shirted "tropomyosins" and "troponins" moved away from the black-shirted "actins," allowing the "myosin chain" to grab the "actin chain" and pull it along. Then Swihart introduced a "mutation" that prevented the teachers who were playing the role of actin from doing their job of binding to myosin. When actin couldn't bind to myosin, muscle contraction stopped. Acting out the roles of "proteins" helped the teachers see the problems that mutations can cause.
Lifton's lecture on the kidney, salt and hypertension laid the groundwork for an osmosis experiment using varying concentrations of salt dissolved in water, with a drop of food coloring distinguishing one from another. The higher the concentration of salt, the more rapidly the fluid permeated a membrane, demonstrating how salt re-absorption in the kidney helps regulate blood pressure. The hotly debated role of dietary salt in the development of hypertension fed a practical discussion of the amount of salt found in everyday foods and how to read labels for information about sodium content.
The teachers left with their own Holiday Lectures videotapes and links to resources on the HHMI Web site. They also took home lesson plans, instructions for experiments and ordering information for supplies.
"The best part of this workshop is that everything is packaged and ready to go for my classroom, said Sarah LaBounty, a first year teacher at New Vista High School in Boulder. "And I've had a chance to do the activities myself."