A patient newly diagnosed with type 1 diabetes asks a nurse, “How does insulin normally work in my body?” The nurse explains that normal insulin has which action in the body?

Choice A reason: Insulin does not stimulate the liver to convert glycogen to glucose; instead, it promotes glycogenesis and inhibits glycogenolysis. By facilitating glucose uptake and storage, insulin lowers blood glucose levels, counteracting the process of glycogen breakdown into glucose, which is regulated by glucagon and other hormones, making this choice incorrect. Choice B reason: Insulin does not promote amino acid synthesis into glucose (gluconeogenesis). It inhibits gluconeogenesis in the liver, reducing glucose production from amino acids and other substrates. By enhancing glucose uptake and storage, insulin maintains glucose homeostasis, making this option incorrect as it misrepresents insulin’s role in glucose metabolism. Choice C reason: Insulin does not stimulate the pancreas to reabsorb glucose. The pancreas produces insulin, which acts on target tissues like muscle and fat to facilitate glucose uptake. Glucose reabsorption occurs in the kidneys, regulated by sodium-glucose cotransporters, not insulin, making this choice scientifically inaccurate for insulin’s function. Choice D reason: Insulin promotes glucose uptake into cells by facilitating GLUT4 transporter translocation to cell membranes in muscle and adipose tissue. This allows glucose to enter cells for energy production via glycolysis and the Krebs cycle. This is insulin’s primary role in maintaining blood glucose homeostasis, making it the correct choice for its action.