The partial negative charge in a molecule of water occurs because ________.

#Question id: 14325

#Section 5: Bioprocess Engineering and Process Biotechnology

Production of recombinant protein by a geneticallyengineered strain of Escherichia coli is proportional to cell growth. Ammonia is used as nitrogen source for aerobic respiration of glucose. The recombinant protein has an overall formula CHI.5500.31N0.25. The yield ofbiomass from glucose is measured at 0.48 g g-1; the yield of recombinant protein from glucose is about 20% that for cells. If the biomass yield remains at 0.48 g g- l, how much change in ammonia requirement for wild-type E. coliunable to synthesise recombinant protein?

#Question id: 14326

#Section 5: Bioprocess Engineering and Process Biotechnology

The chemical reaction equation for conversion of ethanol (C₂H₆0) to acetic acid (C₂H₄0₂) is:

Acetic acid is produced from ethanol during growth of Acetobacter aceti, which has the composition CH_1.80_0.5N_0.2. Biomass yield from substrate is 0.14 g g^{- 1}; product yield from substrate is 0.92 g g^-1. Ammonia is used as nitrogen source. How much gmol of oxygen is demanded for acetic acid production?

#Question id: 14327

#Section 5: Bioprocess Engineering and Process Biotechnology

Bakers' yeast is produced in a 50 000-litre fermenter under aerobic conditions. The carbon substrate is sucrose; ammonia is provided as nitrogen source. The average biomass composition is CH_1.830_0.55N_0.17 with 5% ash. Under efficient growth conditions, biomass is the only major product; the biomass yield from sucrose is 0.5 g g^-I. If the specific growth-rate is 0.45 h^-l, estimate the rate of heat removal required to maintain constant temperature in the fermenter when the yeast concentration is 10 g l^{- 1}     _______________________.10^6

#Question id: 14328

#Section 5: Bioprocess Engineering and Process Biotechnology

In a sewage-treatment plant, a large concrete tank initially contains 440 000 litres liquid and 10 000 kg fine suspended solids. To flush this material out of the tank, water is pumped into the vessel at a rate of 40 000 litres h^{- 1}. Liquid containing solids leaves at the same rate. Estimate the concentration of suspended solids in the tank at the end of 5 h._______________________.

#Question id: 14329

#Section 5: Bioprocess Engineering and Process Biotechnology

During exponential phase in batch culture, the growth rate of a culture is proportional to the concentration of cells present. When Streptococcus lactis bacteria are cultured in milk, the concentration of cells doubles in45 min. If this rate of growth is maintained for 12 h, what is the final concentration of cells relative to the inoculum level?

#Question id: 14330

#Section 5: Bioprocess Engineering and Process Biotechnology

A radioactive isotope decays at a rate proportional to the amount of isotope present. If the concentration of isotope is C (mg l^-I), its rate of decay is:

A solution of the isotope ³²p is used to radioactively label DNA for hybridisation studies. The half-life of ³²p is 14.3 days. According to institutional safety requirements, the solution cannot be discarded until the activity is 1% its present value. How long will this take?____________________