An activated-sludge waste treatment system is required to reduce the amount of BOD₅ from 1000 mg/l to 20 mg/l at the exit. The sedimentation unit concentrates biomass by a factor of 3. Kinetic parameters are µ_m = 0.2 h-1 , K_s = 80 mg/l, k_d = 0.01 h-1 , and Y ^M _X/S = 0.5 g MLVSS/g BOD₅. The flow of waste water is 10000 l/h and the size of the treatment basin is 50,000 l. What is the value of the solids residence time?

#Question id: 4148

#Part-A Aptitude & General Biotechnology

Which of the following is true about the sorting pathway for proteins destined for incorporation into lysosomes or the plasma membrane of eukaryotic cells?

#Question id: 4149

#Part-A Aptitude & General Biotechnology

Glycosylation of proteins inside the endoplasmic reticulum does not involve:

#Question id: 4150

#Part-A Aptitude & General Biotechnology

Posttranslational glycosylation of proteins is inhibited specifically by:

#Question id: 4151

#Part-A Aptitude & General Biotechnology

The signal sequences that direct proteins to the nucleus are:

#Question id: 4152

#Part-A Aptitude & General Biotechnology

The pathway for polypeptides exported from E. coli includes the following steps, which occur in what order for correct export?

1.  A chaperone, SecA, binds to the polypeptide.

2.  A chaperone, SecB, binds to the polypeptide.

3.  ATP is hydrolyzed by Sec A.

4.  SecA pushes 20 amino acids of the polypeptide into the translocation complex.

#Question id: 4153

#Part-A Aptitude & General Biotechnology

Ubiquitin-mediated protein degradation is a complex process, and many of the signals remain unknown.  One known signal involves recognition of amino acids in a processed protein that are either stabilizing (Ala, Gly, Met, Ser, etc.) or destabilizing (Arg, Asp, Leu, Lys, Phe, etc.), and are located at: