2. If Damkohler number, NDa >>1, the reaction rate is much greater than the mass transfer rate and the overall reaction is controlled by the rate of mass transfer. In this case, the enzyme reaction can be described as (where Csb and Cs are the substrate concentration in bulk of solution and at the immobilized enzyme surface respectively. ks mass transfer coefficient, and a is the surface area of an immobilized enzyme particles)
8. To measure the extent to which the reaction rate is lowered because of resistance to mass transfer, the effectiveness factor of an immobilized enzyme, ? can be defined as
Options
A. reaction rate/rate if not slowed by diffusion
B. rate if not slowed by diffusion/ reaction rate
C. actual reaction rate/ rate if not slowed by diffusion
D. rate if not slowed by diffusion/ actual reaction rate
Correct Answer: actual reaction rate/ rate if not slowed by diffusion
9. A fed-batch reactor containing 1 g.l-1 of substrate in 2 litre of medium. It is fed with 1 g.l-l of substrate at the rate of 1 litre per hour. After 10 hours, the concentration of substrate in the reactor was 0.5 g.l-1 . The mass of substrate that was used by the culture in the reactor was
10. A continuous reactor at steady state contains 0.04 g.l-1 of biomass and 0.02 g.l-1 of phenol. The feed contained 0.1 g.l-1 of phenol. The biomass yield would be