Exam 9: Cell Communication

The cell surface receptors that can act only indirectly on plasma membrane-bound enzymes or ion channels are called:

Vasopressin is a hormone that is primarily released when the body is low on water.Release of vasopressin causes the kidneys to conserve water by concentrating urine and decreasing urine output.However,vasopressin also has additional functions in other tissues such as the brain and blood vessels,which are not directly involved in urine production.How could it be possible for vasopressin to trigger different responses in different tissues?

Your research project involves the characterization of a particular signal transduction pathway.Specifically,you have been studying a receptor tyrosine kinase and protein X,which initiates downstream events.You are certain that protein X is part of the signal transduction pathway,but have been unable to identify a direct protein-protein interaction between the receptor tyrosine kinase and the protein X.What should you do next in your attempt to identify a link between the receptor tyrosine kinase and protein X?

What property defines most ligands for intracellular receptors?

What type of receptor is not an enzyme,but is directly associated with an enzyme that can hydrolyze GTP?