In current service, 20 kg s^-1 cooling water at 12⁰C must be circulated through a coil inside a fermenter to maintain the temperature at 37⁰C The coil is 150 m long with pipe diameter 12 cm; the exit water temperature is 28⁰C After the inner and outer surfaces of the coil are cleaned it is found that only 13 kg s^-1 cooling water is required to control the fermentation temperature. Calculate the overall heat-transfer coefficient before cleaning. What fraction of the total resistance to heat transfer before cleaning was due to fouling deposits?____________

#Question id: 4149

#Section 3: Genetics, Cellular and Molecular Biology

Glycosylation of proteins inside the endoplasmic reticulum does not involve:

#Question id: 4150

#Section 3: Genetics, Cellular and Molecular Biology

Posttranslational glycosylation of proteins is inhibited specifically by:

#Question id: 4151

#Section 3: Genetics, Cellular and Molecular Biology

The signal sequences that direct proteins to the nucleus are:

#Question id: 4152

#Section 3: Genetics, Cellular and Molecular Biology

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

#Section 3: Genetics, Cellular and Molecular Biology

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:

#Question id: 4155

#Section 3: Genetics, Cellular and Molecular Biology

Of all the possible triplet codons, __ do not code for an amino acid.