Glucose conc

• ·       Hormones are proteins made in glands that are carried in the blood plasma to target cells, having widespread and long-lasting effects.
• ·       Lipid soluble hormones are able to pass through their target cell’s membrane and bind to receptors in the cell, whereas water soluble hormones bind to receptors on the surface of the cell.
• ·       The pancreas is a gland made mostly of cells that produce digestive enzymes such as amylase and lipase with a scattering of groups of hormone-producing cells called islets of Langerhans.
• ·       These islets of Langerhans have alpha cells that produce glucagon and beta ones that produce insulin, both which affect blood glucose concentration.
• ·       When blood glucose concentration is too high, insulin is secreted which enacts several changes such as: changing the tertiary structure of and increasing the number of glucose carrier proteins, activating enzymes that do glycogenesis (conversion of glucose to glycogen in the liver) and activating enzymes that convert glucose to fat.
• ·       When blood glucose concentration is too low, glucagon is secreted which enacts several changes such as: activating to receptors on the surface of liver cells, activating enzymes that do glycogenolysis (breakdown of glycogen to glucose) and activating enzymes that do gluconeogenesis (production of glucose from other sources such as fat and protein).
• ·       Adrenaline is a hormone produced by the adrenal glands that can enact similar changes as glucagon to increase blood glucose concentration.
• ·       Glucagon and adrenaline both use a method of action called the secondary messenger model, where they bind to a protein receptor on the surface of a liver cell, this protein changes shape and activates an enzyme called adenyl cyclase that converts ATP to cyclic AMP, this cAMP binds to and activates protein kinase enzyme, which finally catalyses glycogenolysis.
• ·       The interaction of different hormones allows highly sensitive control of blood glucose concentration.