A protein binds to phosphocellulose column at pH 7.0 and elutes at pH 8.0. If the protein has to be further purified on a DEAE Sephacel column, the binding buffer should have a pH of

Which of the following techniques is best suited for immobilizing an affinity ligand?

A. Physical adsorption

B. Gel entrapment

C. Crosslinking with a polymer

D. Covalent linkage to a spacer arm

Which one of the following can not be a limiting substrate if Monod's growth kinetics is applicable?

A. Extracellular carbon source

B. Extracellular nitrogen source

C. Dissolved oxygen

D. Intracellular carbon source

During cultivation of microorganisms in a fermenter, various parameters are controlled by appropriate sensor (probe). Match each probe in Group I with the appropriate response mechanism in Group II.

A. P-2, Q-3, R-1, S-4

B. P-1, Q-2, R-4, S-3

C. P-3, Q-2, R-4, S-1

D. P-3, Q-4, R-2, S-1

The kinetics of the disintegration of baker's yeast cells in a bead mill is described as $$\frac{{dp}}{{dt}} = K\left( {{P_m} - P} \right)$$   , where P is the concentration of protein released, m is the maximum protein concentration achievable, K is the first order rate constant and is 0.5 h⁻¹ for the system studied. The time required for the release of 90% of the intracellular proteins will be:

A. 10 h

B. 0.2 h

C. 4.6 h

D. None of the above