Thursday, June 25, 2009

cells as function machines


06.12.09. Cells are often thought of as machines, in the sense that they take an input and produce an output in order to perform a biological function. Upon measuring the input and output experimentally, one might hope to describe the biological function of the cell quantitatively with a mathematical function. Mathematical functions, and the notion that an equation can take an input and produce an output, had recently been introduced to the students. In this exercise, students were presented with several types of "virtual cells" on the computer, each of which took in numbers of the students' choosing and spit out corresponding numbers according to a (hidden) mathematical expression (source code in MATLAB is available by request to ajm2121(at)columbia.edu). As a class, students tried many inputs until they noticed a pattern, plotted their input/output pairs as a graph, and figured out each hidden algebraic function.