Role of Hormones in Metabolism

Flashcards about the roles of insulin and glucagon in metabolism.

Diabetes Mellitus

A metabolic disorder characterized by high blood glucose levels, linked to cardiovascular disease, weight loss, kidney issues, and vision impairment.

Insulin

A hormone produced by pancreatic beta cells that responds to high blood glucose, signaling cells to absorb glucose.

Insulin Release Mechanism

Glucose enters beta cells via protein transporters, high ATP closes potassium channels, calcium influx triggers cascade, resulting in insulin-filled vesicles releasing insulin into bloodstream.

Insulin-independent tissues

Tissues that do not require insulin for glucose uptake, such as the liver and brain.

GLUT4 transporters

Facilitate glucose uptake in target cells via facilitated diffusion.

Other Effects of Insulin

Upregulates glycogen synthesis, inhibits glycogen breakdown and gluconeogenesis, and also promotes lipid storage and triglyceride synthesis.

Type 1 Diabetes

Immune system destroys pancreatic beta cells, resulting in low insulin production.

Type 2 Diabetes

Cells become resistant to insulin, leading to poor cellular glucose uptake.

Glucagon and Insulin

Peptide hormones from the pancreas that act in opposition to regulate blood glucose levels.

Glucagon

Secreted by alpha cells when blood glucose is low, increases blood glucose via glycogenolysis and gluconeogenesis, and promotes lipid breakdown.

Insulin

Promotes glucose uptake by cells, encourages anabolic processes like lipid and protein synthesis and inhibits gluconeogenesis and glycogenolysis.

Fasting State

Energy is low, glucagon is secreted, glycogenolysis and gluconeogenesis is activated and triglycerides are broken down.

Satiety State

Occurs after eating, insulin is released, the liver stores glucose, Lipid synthesis is activated, lipolysis is suppressed.