Insulin signal transduction pathway signals the conversion of the glycogen already stored in the liver cells into glucose. This process is called glycogenolysis. Conversely, when the blood-glucose levels are too high, the pancreas is signaled to release insulin. Insulin is delivered to the liver and other tissues throughout the body (e.g., muscle, adipose). When the insulin is introduced to the liver, it connects to the insulin receptors already present, that is tyrosine kinase receptor. These receptors have two alpha subunits (extracellular) and two beta subunits (intercellular) which are connected through the cell membrane via disulfide bonds. When the insulin binds to these alpha subunits,
Insulin resistance blood into fat cells. The intake of simple sugars, and particularly fructose, is a factor that contributes to insulin resistance. Fructose is metabolized by the liver into triglycerides, and, as mentioned above, tends to raise their levels in the blood stream. Once established, insulin resistance would result in increased circulating levels of insulin. Since insulin is the primary hormonal signal for energy storage into fat cells, which tend to retain their sensitivity in the face of hepatic and skeletal muscle resistance, IR stimulates the formation of new fatty tissue and accelerates weight gain. Insulin resistance and type 2 diabetes are