Which of the following experimental strategies could be used to block the IP3 branch but not the DAG branch of the signaling pathway that involves phosphatidylinositol-4,5-bisphosphate?
Which of the following experimental strategies could be used to block the IP3 branch but not the DAG branch of the signaling pathway that involves phosphatidylinositol-4,5-bisphosphate?
- addition of a cAMP phosphodiesterase inhibitor
- blocking the GPCR involved
- inhibition of protein kinase A
- inhibition of phospholipase C
- adding an antagonist of the IP3 receptor
What happens during glycogenolysis?
- glucose is synthesized from non-carbohydrate sources
- CO2 is reduced to form carbohydrates
- glycogen is hydrolyzed to release glucose-1-phosphate
- glucose is oxidized, producing ATP by oxidative phosphorylation
- glycogen is phosphorolyzed to release glucose-1-phosphate
Why is the consequence of epinephrine signaling so different for cardiac cells and hepatocytes?
- The epinephrine receptors on the surface of their target cells are different.
- The epinephrine receptors are more abundant on the surface of cardiac cells.
- Different amounts of epinephrine reach each different type of target cell.
- The downstream signaling components stimulated by the activated epinephrine receptor are different in cardiac cells and hepatocytes.
- There is no difference in the responses of these cell types to epinephrine.
Which of the following is involved in propelling mucus across the epithelial layer of the trachea?
- flagella
- cilia
- microfilaments
- All of the above
- Both B and C
Medication to reduce the hepatic glycogenolysis pathway could help to alleviate Type II diabetes.
- True
- False
Calmodulin is activated in the cytoplasm of unstimulated cells, i.e. when Ca2+ levels are 10-4 mM.
- True
- False
You are studying microtubules (MTs) in vitro, and have isolated MTs and their subunits in a test tube. If the critical concentration of tubulin dimers in the test tube is above the critical concentration for the plus end but below the critical concentration for the minus end, what will you observe in this in vitro system?
- The MTs will not change in size.
- The cell would not be able to crawl.
- The MTs will continue to grow at both ends.
- The MTs will get shorter.
- Treadmilling will occur.
Humans ultimately depend on autotrophs for the production of ___________.
- glucose
- oxygen
- none of the above, as humans are chemoautotrophs.
- Both A and B