All Tophat for Bio 314

b

BETA-ARRESTIN BINDS TO PHOSPHORYLATED GPCRS AND ________ A. Inhibits the agonist-bound G-protein coupled receptor. B. Is an adapter protein that links with clathrin. C. Stimulates the heterotrimeric G-protein bound to the receptor. D. Initiates autophagy.

d

Phospho-relay signaling involves A. Consecutive kinase activities that result in a series of phosphorylation events. B. Protein kinases that are held together on a scaffold to speed up the individual phosphorylation events. C. Serine/threonine kinases that can also phosphorylate histidine. D. Transfer of a phosphate group from one histidine to another.

C

WHAT WOULD HAPPEN IF THE IRON IN YOUR CELLS IS TOO LOW IN ORDER TO RECTIFY THE PROBLEM? A.More iron transporter would be synthesized and moved to the plasma membrane. B. Iron-free aconitase would bind to the IRE in the 5' UTR of the transferrin receptor mRNA and prevent its degradation. C. Iron-free aconitase would bind to the IRE in the 3' UTR of the transferrin receptor mRNA and prevent its degradation. D. Iron-free aconitase would bind to the IRE in the 3' UTR of the ferretin mRNA and promote its translation.

b

WHICH OF THE FOLLOWING STATEMENTS ABOUT PLANT SIGNALING IS FALSE? A.G-protein coupled receptors are involved. B. The plant receptor activates the G-protein by promoting GTP binding. C. The plant receptor activates the G protein by promoting GTPase activity. D.A GTP-binding protein exchanges its bound GDP for GTP to become activated.

covalent bond

When atoms share electrons the resulting chemical bond is a

b

Which of the following is true for the plant heterotrimericG-proteins? A. The Gα subunit has high intrinsic GTPase activity. B. The Gα subunit has high intrinsic GTP-GDP exchange activity. C. The ligand activated receptor is a GEF. D. Gα is maintained in the active state for longer when the receptor is phosphorylated and endocytosed.

a

Which of the following statements about microtubules is true? A.Motor proteins move in a directional fashion along microtubules by using the inherent structural polarity of a protofilament. B. The centromere nucleates the microtubules of the mitotic spindle. C. Because microtubules are subject to dynamic instability, they are used only for transient structures in a cell. D.ATP hydrolysis by a tubulin heterodimer is important for controlling the growth of a microtubule.

a

Which of the following statements about molecular switches is false? A. Phosphatases remove the phosphate from GTP on GTP-binding proteins, turning them off. B. Protein kinases transfer the terminal phosphate from ATP onto a protein. C. Serine/threonine kinases are the most common types of protein kinase D. A GTP-binding protein exchanges its bound GDP for GTP to become activated.