TLS Online TPP Program

#Question id: 150


How do the pKa values of an ionizable side chain compare when the amino acid is free versus when it is in a polypeptide chain?

#Section 2: General Biology
  1. The pKa of the side chain is independent of whether the amino acid is in a polypeptide chain or is free.

  2. The pKa of the side chain is always lower for the free amino acid.

  3. The pKa of the side chain may be lower or higher in a polypeptide chain due to weaker inductive effects and differences in their microenvironments.

  4. The pKa of the side chain is usually higher in a polypeptide chain due to stabilization from nearby residues in the three-dimensional structure.

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TLS Online TPP Program

#Question id: 14165

#Section 4: Fundamentals of Biological Engineering

Stoichiometric equations are used to represent growth of microorganisms provided a ' molecular formula' for the cells is available. The molecular formula for biomass is obtained by measuring the amounts of C, N, H, O and other elements in cells. For a particular bacterial strain, the molecular formula was determined to be C4.4H7.30 1.2N0.86 . These bacteria are grown under aerobic conditions with hexadecane (C16H34) as substrate. The reaction equation describing growth is:

                                    

Assuming 100% conversion, what is the yield of cells from oxygen in g g-l?

TLS Online TPP Program

#Question id: 14165

#Section 5: Bioprocess Engineering and Process Biotechnology

Stoichiometric equations are used to represent growth of microorganisms provided a ' molecular formula' for the cells is available. The molecular formula for biomass is obtained by measuring the amounts of C, N, H, O and other elements in cells. For a particular bacterial strain, the molecular formula was determined to be C4.4H7.30 1.2N0.86 . These bacteria are grown under aerobic conditions with hexadecane (C16H34) as substrate. The reaction equation describing growth is:

                                    

Assuming 100% conversion, what is the yield of cells from oxygen in g g-l?

TLS Online TPP Program

#Question id: 14166

#Section 4: Fundamentals of Biological Engineering

Stoichiometric equations are used to represent growth of microorganisms provided a ' molecular formula' for the cells is available. The molecular formula for biomass is obtained by measuring the amounts of C, N, H, O and other elements in cells. For a particular bacterial strain, the molecular formula was determined to be C4.4H7.30 1.2N0.86 . These bacteria are grown under aerobic conditions with hexadecane (C16H34) as substrate. The reaction equation describing growth is:

                             

You have been put in charge of a small fermenter for growing the bacteria and aim to produce 2.5 kg of cells for inoculation of a pilot-scale reactor. What minimum amount of hexadecane substrate must be contained in your culture medium? 

TLS Online TPP Program

#Question id: 14166

#Section 5: Bioprocess Engineering and Process Biotechnology

Stoichiometric equations are used to represent growth of microorganisms provided a ' molecular formula' for the cells is available. The molecular formula for biomass is obtained by measuring the amounts of C, N, H, O and other elements in cells. For a particular bacterial strain, the molecular formula was determined to be C4.4H7.30 1.2N0.86 . These bacteria are grown under aerobic conditions with hexadecane (C16H34) as substrate. The reaction equation describing growth is:

                             

You have been put in charge of a small fermenter for growing the bacteria and aim to produce 2.5 kg of cells for inoculation of a pilot-scale reactor. What minimum amount of hexadecane substrate must be contained in your culture medium? 

TLS Online TPP Program

#Question id: 14167

#Section 4: Fundamentals of Biological Engineering

Corn-steep liquor contains 2.5 % invert sugars and 50% water; the rest can be considered solids. Beet molasses containing 50% sucrose, 1% invert sugars, 18% water and the remainder solids, is mixed with corn-steep liquor in a mixing tank. Water is added to produce a diluted sugar mixture containing 2% (w/w) invert sugars. 125 kg corn-steep liquor and 45 kg molasses are fed into the tank.

 How much water is required?


TLS Online TPP Program

#Question id: 14167

#Section 5: Bioprocess Engineering and Process Biotechnology

Corn-steep liquor contains 2.5 % invert sugars and 50% water; the rest can be considered solids. Beet molasses containing 50% sucrose, 1% invert sugars, 18% water and the remainder solids, is mixed with corn-steep liquor in a mixing tank. Water is added to produce a diluted sugar mixture containing 2% (w/w) invert sugars. 125 kg corn-steep liquor and 45 kg molasses are fed into the tank.

 How much water is required?