Final answer:
The statement about Akt protein kinase being responsible for various metabolic actions of insulin in various cell types including hepatocytes, skeletal muscle, and adipocytes is true. Akt plays a central role in insulin-mediated metabolic pathways, such as glucose uptake, glycogen synthesis, and the regulation of glycolysis.
Step-by-step explanation:
The statement that Akt protein kinase orchestrates the numerous metabolic actions of insulin in hepatocytes, skeletal muscle, and adipocytes is True. Insulin activates numerous signaling pathways, including the ones involving Akt (Protein Kinase B), particularly after binding to its tyrosine kinase receptors on cell surfaces. Upon activation, Akt plays a key role in mediating the metabolic effects of insulin.
Some of the metabolic actions include the activation of metabolism, where insulin stimulates glucose uptake in cells by the translocation of Glut-4 transporters, and enhances glycogen synthesis by activating glycogen synthase. Furthermore, insulin promotes glycolysis for the generation of ATP and fatty acid synthesis, while inhibiting glycogenolysis and gluconeogenesis, processes which are generally involved in raising blood glucose levels. Hence, insulin helps in the reduction of blood glucose levels and storage of excess glucose as glycogen in the liver.