Question 4. a. Solve the analytic solution for the substrate concentration profile in a 1D steady state system, assume the substrate consumption rate is a linear function of substrate concentration, the length of the 1D immobilized matrix is 1cm, and bulk substrate concentration is 1mg/mL : Ddy2d2S=aS, where a is 2/min and D is 2cm2/min b. plot the substrate concentration vs the length of immobilized matrix for three cases: part a, diffusion is very fast (D=20cm2/min and a=2/min), and consumption rate is slow (a=0.02/min and D is 2cm2/min). Gradient of S