Tuesday, July 23, 2019
METABOLISM, Report on any two (2) classes of messengers, that interact Lab
METABOLISM, on any two (2) classes of messengers, that interact with each other, directly or indirectly, to alter the met - Lab Report Example When these glucose levels reach a high level, the pancreas will release insulin that stimulates tissues that are dependent on insulin to take up the excess glucose. Therefore, glucagon is one part of the feedback system, together with insulin, that stabilizes the levels of blood sugar. Glucagon is synthesized in the islets of langerhans by the alpha cells and secreted by the same cells. The islets of langerhans are found in the pancreasââ¬â¢ endocrinal portion and in man1. Glucagon is a peptide hormone with 29 amino acids, and generally, it acts to raise sugar levels present in the blood through promotion of glycogenolysis and gluconeogenesis, which refer to splitting of stored glycogen to glucose sub-units and formation of glucose respectively2. It exists as an inert holoenzyme, pro-glucagon, which is activated by pro-hormone convertase into glucagon. Glycogen is a polymer form of glucose that is similar to starch in plants and is stored in liver hepatocytes. These hepatocytes po ssess receptors for glucagon that bind the hormone. On binding of glucagon, the hepatocytes release glucose from the glycogen polymer released to the blood, for use by other cells through glycogenolysis. Simultaneously, glucagon also binds to hepatocytes and kidney cells and stimulates the synthesis of glucose through the process of gluconeogenesis. Through, shutting down the process of glycolysis, glucagon leads to the shunting of glycolytic intermediates to the reformation of glucose. The hormone also has a minimal on the human process of lipolysis. It appears that production of glucagon depends on the CNS, although the pathways that affect the production of glucagon are yet to be clearly defined. Glucagon dissociates soon after it binds onto the glucagon receptors since they change the configuration after activating cyclic adenosine monophosphate2. The free glucagon is dissociated in the blood by proteolytic enzymes. Cyclic adenosine monophosphate is a nucleoside phosphate, which acts as a second messenger and is of utmost importance in numerous processes in the human body. The messenger is formed from ATP, and the resultant molecule is used in signal transduction within the cell acting in the cyclic adenosine monophosphate dependent pathway3. Adenylate cyclase, which is found on the inner membraneââ¬â¢s inner surface, synthesizes cyclic adenosine monophosphate from the precursor molecule ATP. Adenylate cyclase enzyme undergoes activation through G-protein coupled receptors, whereas it is inhibited by inhibitory G-protein coupled receptors. Adenylate cyclase within the liver and in the muscles is more specific to glucagon than it is to adrenalin3. Cyclic adenosine monophosphate has one phosphate group that is bound to position three and position five of the sugar through two phosphate-ester linkages4. These linkages form a cyclic structure or a ring that is limited by residues of oxygen and phosphorous, as well as by the carbons at position three and fiv e. This explains why it is referred to as cyclic adenosine monophosphate. It is used for signal transductions within human cells for passing on the effects of hormones that cannot pass through the plasma membrane, such as the peptide hormone glucagon. Cyclic adenosine monophosphate is particularly involved in protein kinase activation. It also binds to ion channels and regulates their permeability. Some of
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