Page 438 - Elements of Chemical Reaction Engineering Ebook

Chap.7 Summary 409

and for the weight fraction is

wj = j(1 -p)2p~-I (S7-6)
41.. The enzymatic reaction for the decomposition of urea, S, catalyze~d by
urease, E, is
k,
E+S 7
E*S
k2 (S7-7)
k
W+E*S ---% P+E
It follows Michaelis-Menten kinetics and the rate expression is

(S7-8)

where Vmax is the maximum rate of reaction for a given enzyme con-
centration and K,,, is the Michaelis constant.
5. The total amount of a given enzyme in the system is the sum of the
free enzyme, E, and the. bound enzyme, E * S:

E,=E*S+E (S7-9)
To arrive at Equation (S7-8) we treat each reaction as elemenlary,
apply the PSSH to the complex, and use Equation (S7-9).
6. Bioreaclors:
cells + substrate ---+ more cells + product

(a) Phases of bacteria growth:
1. Lag 11. Exponential 111. Stationary IV. Death
(b) Monod growth rate law:

(S7- 10)

(c) Stoichiometry:
mass of new cells formed
= substrate consumed to produce new cells
(d) Unsteady-state mass balance on a chemostat:

dCc - Cc, - cc
- --+rR-rd (S7-
dt z

(S7-

-rs = YsicrR + Ys/,,rp + mCc (S7-