408 Chapter 10. Enzymes and molecular machines[[Student version, January 17, 2003]]
reversibly inhibited by the addition of urea, a small molecule. The initial rate of this reaction, for
acertain concentrationcE,totof enzyme, is measured in terms of the initial sucrose concentration,
both with and without a 2Msolution of urea:
csucrose(M) 0.0292 0.0584 0.0876 0.117 0.175 0.234
v(no urea) (Ms−^1 ) 0.182 0.265 0.311 0.330 0.372 0.371
v(with urea) (Ms−^1 ) 0.083 0.119 0.154 0.167 0.192 0.188Make the appropriate Lineweaver–Burk plots and determine whether the inhibition by urea is
competitive in character. Explain.