Each of the following are steps in the G Protein Coupled Receptor signalling pathway EXCEPT Select one: a. Protein kinase is activated. b. GTP donates a phosphate group to an inactive protein kinase. c. A specific protein is activated via phosphorylation to generate a response. d. A signal molecule binds to a membrane receptor protein.

Each of the following are steps in the G Protein Coupled Receptor signalling pathway EXCEPT
Select one:
a. Protein kinase is activated.
b. GTP donates a phosphate group to an inactive protein kinase.
c. A specific protein is activated via phosphorylation to generate a response.
d. A signal molecule binds to a membrane receptor protein.

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Answer

• b. GTP donates a phosphate group to an inactive protein kinase.
  Explanation:
  The three basic steps in G protein coupled receptor signaling are: binding of signal to the receptor, passing the signal through intermediate molecules and phosphorylation of the target proteins by the kinase which causes cellular changes. Protein kinase is activated by the signal from G protein through cAMP. The activated protein kinase further phosphorylates the receptor.

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