Enzyme Lab Report

catalysed by the transmembrane protein, adenylate cyclase, initiated by the release of GTP-bound α subunit. This increases the cytosolic levels of cAMP which then activates protein kinase A. This successively phosphorylates glycogen phosphorylase b stored in the cell, as phosphorylase kinase is initiated. Phosphorylation of glycogen phosphorylase b converts to phosphorylase a. This enzyme releases glucose-1-phosphate from glycogen polymers. After this the phosphate group is moved from the C-1 position to the C-6 position creating glucose-6-phosphate by the enzyme, phosphoglucomutase. The enzyme glucose-6-phosphatase removes the phosphate group from glucose-6-phosphate, leaving free glucose molecules. These glucose molecules leave the cell via …show more content…
These are found on the surface of liver, muscle and fat cells. Blood flow from the pancreas drains into the hepatic portal vein which drains into the liver. Insulin secreted by the beta cells enters the blood flow of the pancreas which drains into the hepatic portal vein and into the liver. Insulin stimulates the synthesis of glycogen in liver cells. This is done by the glycogenesis pathway, where glucose molecules are added to chains of glycogen for storage. Either glucokinase or hexokinase catalyse the conversion of glucose into glucose-6-phosphate which is then converted into glucose-1-phosphate by the enzyme phosphoglucomutase. UDP-glucose phosphorylase enzyme catalyses the conversion of glucose-1-phosphate into UDP-glucose. Two phosphate molecules are formed when pyrophosphate is later hydrolysed by pyrophosphatase. The tyrosine residue the subunits of glycogenin act as anchors for the reducing end of glycogen. To this, eight UDP-glucose molecules are added, forming α(1 → 4) bonds, till a chain of eight glucose monomers is formed. Glycogen synthase then binds to the glycogen chain. This storing of glucose in liver cells, decreases the concentration of glucose in the