TOPICS: Insulin, insulin synthesis, actions of insulin, insulin regulation, lipogenesis, glycolysis, GLUT-4, beta cells, pancreatic islets, preproinsulin, proinsulin, C-peptide, glucose, exocytosis, incretins, GLP-1, DPP-4, sitagliptin, liraglutide, exenatide, glucagon, hypoglycemia, fasting state, fed state, glycogenolysis, lipase, gluconeogenesis, glycogen phosphorylase, ketones, actions of glucagon, glucagon synthesis, glucagon regulation, alpha cells, pancreatic islet cells, hypoglycemia, fasting, starvation, lipolysis, ketone production, proteolysis