The function of light is to excite a specialized chlorophyll in the reaction centre either by Direct absorption or more frequently, via energy transfer from an antenna pigment, This excitation process can be envisioned as

a.) An electron from the lowest-energy filled orbital of the chlorophyll to the highest-energy unfilled orbital

b.) An electron in the upper orbital is only tightly bound to the chlorophyll and is difficult to fetch the electron nearby molecules

c.)  The electron in the upper orbital is only loosely bound to the chlorophyll and is easily lost if a molecule that can accept the electron is nearby

d.) The promotion of an electron from the highest-energy filled orbital of the chlorophyll to the lowest-energy unfilled orbital

Which combination is CORRECT?

#Question id: 14198

#Section 5: Bioprocess Engineering and Process Biotechnology

which of the following do not come under continuous filtration?

#Question id: 14199

#Section 5: Bioprocess Engineering and Process Biotechnology

#Question id: 14200

#Section 5: Bioprocess Engineering and Process Biotechnology

A fluidized-bed, immobilized-cell bioreactor is used for the conversion of glucose to ethanol by Z. mobilis cells immobilized in k-carrageenan gel beads. The dimensions of the bed are 10 cm (diameter) by 200 cm. Since the reactor is fed from the bottom of the column and because of CO₂ gas evolution, substrate and cell concentrations decrease with the height of the column. The average cell concentration at the bottom of the column is X₀ = 45 g/l, and the average cell concentration decreases with the column height according to the following equation:

where Z is the column height (cm). The specific rate of substrate consumption is q_S = 2 g S/g cells . h. The feed flow rate and glucose concentration in the feed are 5 l/h and 160 g glucose/l, respectively.

Determine the ethanol concentration in the effluent (g/l . h) if YP/S = 0.48 g ethanol/g glucose

#Question id: 14201

#Section 5: Bioprocess Engineering and Process Biotechnology

A fluidized-bed, immobilized-cell bioreactor is used for the conversion of glucose to ethanol by Z. mobilis cells immobilized in k-carrageenan gel beads. The dimensions of the bed are 10 cm (diameter) by 200 cm. Since the reactor is fed from the bottom of the column and because of CO₂ gas evolution, substrate and cell concentrations decrease with the height of the column. The average cell concentration at the bottom of the column is X₀ = 45 g/l, and the average cell concentration decreases with the column height according to the following equation:

where Z is the column height (cm). The specific rate of substrate consumption is q_S = 2 g S/g cells . h. The feed flow rate and glucose concentration in the feed are 5 l/h and 160 g glucose/l, respectively.

Determine the ethanol productivity (g/l . h) if YP/S = 0.48 g ethanol/g glucose.

_______________

#Question id: 14202

#Section 5: Bioprocess Engineering and Process Biotechnology

In a fluidized-bed biofilm reactor, cells are attached on spherical plastic particles to form biofilms of average thickness L = 0.5 mm. The bed is used to remove carbon compounds from a waste-water stream. The feed flow rate and concentration of total fermentable carbon compounds in the feed are F = 2 l/h and S = 2000 mg/l. The diameter of the column is 10 cm. The kinetic constants of the microbial population are r_m = 50 mg S/cm³. h and K_S = 25 mg S/cm³ . The specific surface area of the biofilm in the reactor is 2.5 cm² /cm³ . Assuming first-order reaction kinetics and an average effectiveness factor of n = 0.7 throughout the column, determine the required height of the column for effluent total carbon concentration of S_0i = 100 mg/l.

#Question id: 14203

#Section 5: Bioprocess Engineering and Process Biotechnology