Biochemistry, Physical Science
Cornell University professor Brian Crane says one of the best parts of his career as a chemist has been the element of surprise. Following his curiosity and pursuing opportunities as they arise has kept his research moving into exciting new directions, and led to discoveries about biological systems including circadian rhythms, bacterial chemotaxis, and nitric oxide signaling. Outside of his lab, Crane is working to ensure that all students have the support they need to find opportunity in the sciences and let their curiosity lead them to their own successes.
Crane did his graduate work at Scripps Research Institute in California, studying in a new graduate program focusing on the interface of biology and chemistry. That was a new frontier when he arrived in 1990, and he remembers a sense of excitement and possibility among his classmates. There, he became interested in biochemical reactions that were “a little outside of traditional organic chemistry” – those that involved metal ions, or photons of light, or the movement of electrons between molecules.
He maintained that interest as he set up his own lab at Cornell, turning his attention to biological systems in which such reactions had so far been poorly studied. Scientists had recently discovered the proteins that drive circadian rhythms, but little was known about the light-sensing proteins that keep them in sync. Crane's work showed how light causes conformational changes in photosensors, and how those changes drive subsequent reactions. His team also investigated electron-flux-sensing proteins that bacteria use to navigate a chemical gradient – moving toward food or away from toxins. This work led to understanding how large assemblies of molecules at the cell membrane enable sensing. He's also shown how protein structure affects nitric oxide sensing and the details of how electrons move between different protein molecules. Redox reactions drew him into these research areas, Crane says, but new questions quickly opened up. Today his lab continues to investigate how the structure of these systems' components underlie their function.
Crane teaches all levels of chemistry at Cornell, and mentors undergraduates and high school students in his own lab. He has served on committees to revise both the biology and the chemistry curricula, making the programs more flexibility while retaining their rigor. “We want to make sure the courses are serving as wide a community as possible,” he says.
Some of Crane's most ambitious educational initiatives can be traced back to an experience he had as an undergraduate, when he participated in a program at the University of Manitoba to support aboriginal students. As he got to know the students he tutored in chemistry during his junior and senior years, he realized they faced social and personal challenges that were unfamiliar to him. “They didn't have the same sorts of opportunities that I did, but they really wanted to succeed,” he recalls. “With a little help they could do a lot better.”
Today, Crane is working to create opportunities and provide support for underrepresented minorities in the sciences. Convinced that the best opportunity to foster students' natural curiosity is in their middle school years, he has spent summers in south Chicago teaching physical science with High Jump, a program that offers academic enrichment and support to students of limited economic means, so that they can attend and excel at the city's top high schools.
At Cornell, Crane has worked to strengthen the university's support of undergraduates from groups underrepresented in the sciences. In 2008, while teaching introductory chemistry he and colleague Professor Stephen Lee recognized the need to revamp a summer program aimed to equip students who arrive at Cornell less prepared than their classmates with the quantitative skills they need to succeed in their first-year chemistry course. “If you take a freshman chemistry problem and you know nothing about chemistry, it looks like a foreign language to you,” he says. “So we're teaching physical science almost like a language.” Students in the new course work in peer-led teams to solve problems that build physical intuition: they practice thinking about the physical relationships between things and how to map new concepts onto familiar ones. “You have to put the time in,” he says. “You have to speak the language.”
The program has made a difference. “Students who go through that program perform statistically just like any other group of Cornell students in freshman chemistry,” Crane says. That's encouraging, but Crane thinks he and his colleagues can do better. He wants to extend the support to see his students through more advanced chemistry courses and a firsthand research experience. As an HHMI professor, Crane will extend the program for underrepresented students: a new preparatory course for organic and biochemistry, taken the summer before students' sophomore year, will follow the same model as the pre-freshman course. That course will also introduce students to laboratory work, readying them for independent, mentored research in a Cornell laboratory during a subsequent summer. Additionally, he will open to all students a new course that uses the same teaching strategies as the pre-freshman summer course. “The methodology works, so we want to offer that opportunity to more students,” he says.