Bringing enzymes to deaf
and hard-of-hearing students

Published December 01 2016

Pop-It Beads help deaf and hard-of-hearing students understand the fundamentals of enzyme catalysis. PHOTO PROVIDED BY AUSTIN GEHRET

As a faculty member at the National Technical Institute for the Deaf, my job in higher education is unusual. I work exclusively with deaf and hard-of-hearing students.

The NTID, hosted within Rochester Institute of Technology as one of nine colleges on campus, was established as the first institution devoted to the technical and professional postsecondary education of deaf and hard-of-hearing students. The wealth of resources available through the NTID’s presence attracts many deaf and hard-of-hearing students to the institute’s other colleges as well. I serve as an instructor within the NTID for our associate degree in laboratory science technology but also as a tutor for the baccalaureate-level deaf and hard-of-hearing students in other colleges within the institute. This latter role places me in the unique position of academically supporting deaf and hard-of-hearing students taking classes taught by other nonsigning faculty members. My peers and I serve these support faculty roles to ensure all deaf and hard-of-hearing students at Rochester Institute of Technology achieve equal access to the lecture material presented in their classes.

When I was hired, I needed time to develop my sign-language skills, so I assumed a support role initially to tutor deaf and hard-of-hearing students in biochemistry coursework. When I had developed sufficient sign-language skills, I then had the opportunity to teach the basics of enzyme catalysis in my own biotechnology class at the NTID.

Foundational concepts in biochemistry have been shown to be misconstrued by many students (1, 2). Enzyme kinetics is certainly no exception to this phenomenon (3, 4). Many biochemistry instructors see a noticeable change in students’ expressions when enzyme kinetics becomes the topic of discussion. A good number of students weakly retain concepts of kinetics, but, with the wealth of conceptual information presented on top, it is simply too much for them to absorb.

In my role as tutor, I too was presented with some blank stares. But I had the additional challenge of the limited time I had to figure out where my tutees were disconnecting from the material.

To help with comprehension, I developed visual tutorials to supplement what I could not convey effectively through sign language. I wanted students to develop a deeper understanding of this topic beyond memorization of the Michaelis–Menten equation and how to extrapolate kinetic parameters. In doing so, I devoted significant effort to clarifying the simplifying approach of measuring the initial rate (V0) of enzyme catalysis as well as the steady-state assumption.

As a teacher of deaf and hard-of-hearing students at NTID, direct instruction is not simply an exercise of lecturing in American Sign Language. Our students’ communication preferences and academic needs are extremely diverse. Several students in our LST program do not rely on signed communication, so I lecture by speaking and signing at the same time. Presenting scientific material through two different language channels simultaneously introduces its own set of challenges. Because of this, inclusive learning activities become part of my communication strategy.

I was fortunate to have at my disposal a department stockroom that had accumulated over the years a variety of educational resources. When I came upon a Pop-It Beads DNA modeling kit, I was inspired to develop a kinesthetic activity that could supplement my teaching of enzyme catalysis.

Students were presented with two bins, each containing several pairs of connected Pop-It Beads that acted as the substrate. The students would act as enzymes to separate the beads into individual products in one bin (which represented the products of the catalyzed reaction) while leaving the second bin untouched (which represented the uncatalyzed reaction). In performing the activity, the students could quantitate their influence on this reaction by determining and comparing their catalyzed rate to that of the uncatalyzed reaction. To model molecular behavior effectively, students were instructed to avert their eyes from the substrate bins while catalyzing. We didn’t use blindfolds because that would have restricted many students’ ability to communicate with their partners.

In the few years running this activity, the effect of substrate depletion on catalytic function appears to be its most tangible feature. Most students view the fixed amount of time given to catalyze as a challenge to find and break down all substrates. However, each of them discovers this task becomes increasingly difficult to achieve the longer catalysis continues. Their collective demeanor reflects this struggle. Allowing students to internalize this experience appears to be a more effective way for me to teach substrate depletion effects than to have me lecture about it. Students observe this phenomenon when they quantitate enzyme activity, so it’s a nice opportunity for them to see their classroom experience translate to the laboratory.

Kinesthetic approaches have been used before to model Michaelis–Menten kinetics with a variety of objects (5–8). This activity allows students to model basic dynamics of an enzyme-catalyzed reaction that I feel also holds value in its ability to demonstrate the importance of measuring V0. Based on my tutoring experiences, providing students with opportunities to revisit foundational concepts in novel ways may help them navigate applied topics a little more confidently in their biochemistry courses.


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  2. Sears, D. W., et al. Biochem. Mol. Biol. Educ. 35, 105–118 (2007).
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  4. Linenberger, K. J. & Bretz, S. L., Biochem. Mol. Biol. Educ. 43, 213–222 (2015).
  5. Hinckley, G. J., Chem. Educ. 89, 1213–1214 (2012).
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  7. Ragsdale, F. R., & Pedretti, K. M., Am. Biol. Teach. 66, 621–626 (2004).
  8. Runge, S. W., et al. CBE Life Sci. Educ. 5, 348–352 (2006).
Austin Gehret Austin Gehret is an assistant professor at the National Technical Institute for the Deaf. The institute is part of the Rochester Institute of Technology.