Difference between revisions of "Glycogenolysis"
(New page: '''Glycogenolysis''' is the chemical process by which glycogen is broken down into smaller molecules - normally glucose-6-phosphate. In the liver, the glucose-6-phosphate is furthe...) |
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'''Glycogenolysis''' is the chemical process by which [[glycogen]] is broken down into smaller molecules - normally [[glucose-6-phosphate]]. In the liver, the glucose-6-phosphate is further modified to glucose, and is released into the bloodstream. In muscle tissue, the glucose-6-phosphate is used as fuel by the muscle cell and is not released. | '''Glycogenolysis''' is the chemical process by which [[glycogen]] is broken down into smaller molecules - normally [[glucose-6-phosphate]]. In the liver, the glucose-6-phosphate is further modified to glucose, and is released into the bloodstream. In muscle tissue, the glucose-6-phosphate is used as fuel by the muscle cell and is not released. | ||
| − | Glycogenolysis has two main steps; the first step, in which a glucose molecule is removed from the glycogen molecule as a [[glucose-1-phosphate]] molecule, and a second step in which the glucose-1-phosphate is converted to | + | Glycogenolysis has two main steps; the first step, in which a glucose molecule is removed from the glycogen molecule as a [[glucose-1-phosphate]] molecule, and a second step in which the glucose-1-phosphate is converted to glucose-6-phosphate. |
Glycogen is a branched molecule, and the enzyme that clips a glucose-1-phosphate off the end of a branch, [[glycogen phosphorylase]], stops working when it is less than 5 glucose subunits of a branching point. A second set of two molecules, the [[debranching enzyme]], is then required to remove the branching point so that glycogen phosphorylase can continue working. | Glycogen is a branched molecule, and the enzyme that clips a glucose-1-phosphate off the end of a branch, [[glycogen phosphorylase]], stops working when it is less than 5 glucose subunits of a branching point. A second set of two molecules, the [[debranching enzyme]], is then required to remove the branching point so that glycogen phosphorylase can continue working. | ||
Glycogenolysis is stimulated by the [[endocrine]] [[hormones]] [[glucagon]] and/or [[epinepherine]]. | Glycogenolysis is stimulated by the [[endocrine]] [[hormones]] [[glucagon]] and/or [[epinepherine]]. | ||
Revision as of 16:33, November 22, 2008
Glycogenolysis is the chemical process by which glycogen is broken down into smaller molecules - normally glucose-6-phosphate. In the liver, the glucose-6-phosphate is further modified to glucose, and is released into the bloodstream. In muscle tissue, the glucose-6-phosphate is used as fuel by the muscle cell and is not released.
Glycogenolysis has two main steps; the first step, in which a glucose molecule is removed from the glycogen molecule as a glucose-1-phosphate molecule, and a second step in which the glucose-1-phosphate is converted to glucose-6-phosphate.
Glycogen is a branched molecule, and the enzyme that clips a glucose-1-phosphate off the end of a branch, glycogen phosphorylase, stops working when it is less than 5 glucose subunits of a branching point. A second set of two molecules, the debranching enzyme, is then required to remove the branching point so that glycogen phosphorylase can continue working.
Glycogenolysis is stimulated by the endocrine hormones glucagon and/or epinepherine.
