E. coli have a maximum respiration rate, qO2max, of about 240-mg O2/g-dry wt-h. It is desired to achieve a cell mass of 20 g dry wt/l. The kLa is 120 h-1 in a 1000-l reactor (800 l working volume). A gas stream enriched in oxygen is used (i.e., 80% O2) which gives a value of C* = 28 mg/L. If oxygen becomes limiting, growth and respiration slow; for example,

                                     

   where CL is the dissolved oxygen concentration in the fermenter. What is CL when the cell mass is  at 20 g/l?

#Question id: 1128

#Section 3: Genetics, Cellular and Molecular Biology

During the epinephrine stimulated conversion of glycogen to glucose 1-phosphate, which of the following steps involves protein phosphorylation?

a. inactivation of glycogen synthase               b. activation of protein kinase A

c. activation of adenylyl cyclise                      d. activation of glycogen phosphorylase

#Question id: 1129

#Section 3: Genetics, Cellular and Molecular Biology

Which of the following plays a role in the relaxation of smooth muscle cells by nitric oxide?

a. cGMP          b. protein kinase A      c. protein kinase G      d. guanylyl cyclise

#Question id: 1130

#Section 3: Genetics, Cellular and Molecular Biology

In muscle cells, glycogen phosphorylase kinase is activated by

a. Ca2+.           b. diacylglycerol.   c. nitric oxide.       d. protein kinase A.    

#Question id: 1133

#Section 3: Genetics, Cellular and Molecular Biology

What tertiary structure characterizes all cytokines?

#Question id: 1134

#Section 3: Genetics, Cellular and Molecular Biology

Arrange the following proteins in the proper order in which they become activated in the MAPK signaling pathway:

a. MAP kinase                         b. MEK           c. Ras              d. Raf              e. RTK            

#Question id: 1136

#Section 3: Genetics, Cellular and Molecular Biology

Which of the following signaling pathways can be activated by activation of receptor tyrosine kinases?

a. phospholipase Cγ                b. PI-3 kinase

c. MAP kinase                         d. none of the above