A bacterial culture having a specific oxygen uptake rate of 5 mmol O2 (g DCW)⁻¹ h⁻¹ is being grown aerobically in a fed-batch reactor. The maximum value of the volumetric oxygen transfer coefficient is 0.18 s⁻¹ for the stirred tank bioreactor and the critical dissolved oxygen concentration is 20% of the saturation concentration (8 mg L⁻¹). The maximum density to which the cells can be grown in the fed-batch process, without the growth being limited by oxygen transfer, is approximately

#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

#Question id: 1137

#Section 3: Genetics, Cellular and Molecular Biology

A loss-of-function mutation in PTEN phosphatase results in

a. increased cell proliferation.            

b. decreased cell proliferation.

c. increased apoptosis.                                   

d. decreased apoptosis.

#Question id: 1138

#Section 3: Genetics, Cellular and Molecular Biology

A loss-of-function mutation in Wnt would have a phenotype similar to a

a. gain-of-function mutation in GSK-3.                    

b. gain-of-function mutation in β-catenin.

c. loss-of-function mutation in GSK-3.                     

d. loss-of-function mutation in β-catenin.