Question

1. Liver cells were homogenized, the membranes were separated from the cytoplasm, and then epinephrine was added to only the membrane portion, (assume ATP and GTP were added to membrane fraction). Check all that will occur.

		adenylyl cyclase will be activated.
		Receptor will be activated
		PKA will be activated
		G-proteins will be activated. -
		cAMP will be produced.

Answer 1

Answer-

According to the given question-

In this experiment the Liver cells were homogenized, after that the homogenized sample was centrifuged to get supernatant which contains cytoplasm and the pellets which contains membrane and their debris. The pellets were separated from supernatant and then hormone epinephrine was added to the membrane portion along with  ATP and GTP.

This experiment was conducted by Earl Sutherland during their research to find the action of glycogen phosphorylase enzyme. Earl Sutherland first homogenized the  liver tissue and separates the cytoplasmic and membrane components. the membrane content have enzyme as well as receptor for epinephrine. After that hormone Epinephrine was added to  the fraction containing membrane and incubated followed by centrifugation to get the supernatant by removing membranes component. He also prepare a small sample that have only cytoplasm fraction assayed for glycogen phosphorylase activity and he observed the glycogen phosphorylase in cytoplasmic fraction. From this experiment he concluded that a second messenger which is soluble was produced due to epinephrine when binds to its receptor present in the membrane and after that diffuses into the cytoplasm for activation of enzyme. He identified cAMP which work as second messenger that are involved in action of epinephrine. adenylyl cyclase convert ATP into cAMP .

• When a first messenger binds to the G protein coupled receptor and activate it
• Then An inacive G protein have already bound with GTP binds with the activated receptor.
• Receptor activate G protein by releasing GDP from G protein and attaches GTP to it.
• Activated G ptotein dissociated from receptor and binds with the effector molecule adenyl cyclase
• Activated adenyl cyclase convert ATP into second messenger cAMP .
• cAMP activates the cAMP dependent protein kinase which activate phosphoryl kinase and causes phosphorylation.

So the correct options for this question is all  given options for this answer is true.