Question

all membrane proteins known as g-proteins:

a. mediate the effects of insulin on cells

b.hdrolyze gtp

c.are gated ion channels

d.have a subunit that activates adenylate cyclase

Answer 1

The membrane proteins g proteins function in:-

all the above. They mediate the effects of insulin on cells, hydrolyze GTP, are gated ion channels and have a subunit for adenyl cyclase activation.

ION CHANNELS:The heterotrimeric GTP-binding protein (G protein) mediate the transfer of information across the plasma membrane, from receptor to effector.  G-protein-coupled neurotransmitters and hormones initiate regulatory pathways through ion channels through interaction between G protein subunit and channel protein.

GTP HYDROLYSIS:G proteins exist as a complex of three subunits: alpha,beta, and gamma.The alpha chains contain the sites for binding and hydrolysis of GTP, for ADP-ribosylation by cholera and pertussis toxins, and for specific recognition of receptors and effector molecules.

ACTIVATION OF ADENYL CYCLASE:G proteins play a central role in the transduction process and that the basic format used for transduction in the hormone stimulated adenylyl cyclase system.

INSULIN MEDIATOR: G proteins may mediate the control of several of insulin's intracellular functions. These include the regulation of the MAP kinase pathway, the activation of phospholipase D and the regulation of glucose uptake.