Review Questions - Membranes, Transport and Signaling

Question 0

Palytoxin is a water-soluble polyalcohol toxin produced by dinoflagellate algae. Because of global warming, Ostreopsis has spread from tropical to temperate waters. It may show up in seafood from these waters. PTX is particularly dangerous because it is not destroyed by cooking. Ingestion marked by rhabdomyolysis, cramping, nausea, vomiting, diarrhea…….. PTX binds to the extracellular domain of Na+/K+ ATPase, turning it into a permanently open ion channel. After poisoning with PTX, the concentrations of Na, K+ and Ca2+ in cytosol would change as follows:

Answer 0

Na+ elevated, K+ reduced, Ca2+ elevated

Question 1

In a membrane, which of the following is most likely to be found in the interior of the bilayer, away from water?

Answer 1

Carbon chains of fatty acids

Question 2

The thyroid is stimulated into releasing thyroid hormone by TSH produced in the pituitary and transported by the bloodstream. This type of hormonal signaling is called

Answer 2

Endocrine

Question 3

Generally, steroid hormones

Answer 3

Bind to intracellular receptors

Question 4

Acetylcholine (Ach) binding to the M1 muscarinic receptor in brain results mainly in

Answer 4

Formation of diacylglycerol (DAG)/inositol 1,4,5-triphosphate (IP3)

Question 5

Histamine H2 receptors stimulate gastrointestinal motility and secretion of digestive juices. H2 receptor antagonists such as cimetidine and ramitidine are used to treat peptic ulcers. They lead to

Answer 5

Decreased production of cAMP