Term
| why is glycogen used in metabolism |
|
Definition
| dietary glucose is unreliable, gluconeogenesis is slow so their is a gap it fills when glucose isnt taken in |
|
|
Term
| what parts of the body release sugar |
|
Definition
|
|
Term
| why isnt sugar released from the muscle |
|
Definition
| it is degraded when ecercising |
|
|
Term
| where is glycogen mainly stored |
|
Definition
| skeletal muscle and liver |
|
|
Term
|
Definition
| skeletal muscle, liver, kidney |
|
|
Term
| what is the only organ that does not use glycogen for itself |
|
Definition
|
|
Term
| how is glycogen involved in weight gain |
|
Definition
| it holds water which increases its weight |
|
|
Term
| describe the structure of glycogen |
|
Definition
| branched chain of a-D-glucose with a1-4 and a1-6 bonds that make large granules |
|
|
Term
| where are the enzymes to make or break glycogen located |
|
Definition
| associated with the glycogen granules |
|
|
Term
| give a general explination of how glycogen is made |
|
Definition
| glucose-1-p + UDP -> UDP glucose, UDP glucose adds onto glycogenin one at a time, every 8 residues there is a branch made |
|
|
Term
| what catalizes glucose-1-phosphate + UDP -> UDP glucose |
|
Definition
| UDP glucose phosphorlyase |
|
|
Term
| what catalizes the first 4 residues being put on glycogenin protein |
|
Definition
|
|
Term
| what catalizes more than 4 residies being added to glycogenin protein |
|
Definition
|
|
Term
| what type of bonds does glycogen synthase make |
|
Definition
|
|
Term
| why does glycogen have branches |
|
Definition
| to give more ends for synthesis that glucose can be liberated from |
|
|
Term
| how is a glycogen branch made |
|
Definition
| glycogen synthase puts on more than 8 branches, 6 are cleaved off and moved down the molecule by branching enzyme |
|
|
Term
| what type of bonds do branching enzyme make |
|
Definition
|
|
Term
| what is another name for branching enzyme |
|
Definition
|
|
Term
| what does glycogen phosphorlyase do |
|
Definition
| cleave a1-4 bonds of glycogen yielding glucose 1-phosphate |
|
|
Term
| what is the rate limiting step in glycogen degredation |
|
Definition
|
|
Term
| why and where does glycogen phosphorlyase stop cleaving (other than hormones and such) |
|
Definition
| it reaches steric hinderance near a branch approx 4 residues from it |
|
|
Term
| how are branches removed from glycogen |
|
Definition
| debranching enzyme uses 4/4 transferase and 1/6 glucosidase activity |
|
|
Term
| what does glycogen phosphrlyase need to work |
|
Definition
|
|
Term
|
Definition
|
|
Term
| what is the 4/4 transferase activity |
|
Definition
| debranching enzyme removes 3 of the 4 glucose and attaches them to another branch making a longer chain so glycogen phosphorlyase can act on it |
|
|
Term
| what is the 1/6 glucosidase activity |
|
Definition
| debranching enzyme cleaves the branch point of glucogen, yielding free glucose |
|
|
Term
| what turns glucose-1-phosphate into glucose-6-phosphate |
|
Definition
|
|
Term
| what turns glucose-6-phosphate into glucose |
|
Definition
|
|
Term
| what is an alternative way for glycogen to be broken down |
|
Definition
| lysosomal alpha glucosidase in the lysosome |
|
|
Term
| explain how, after degrading glycogen, it can be used for energy |
|
Definition
| the product of the degredation is glucose-1-phosphate, it can be converted to glucose-6-phosphate and into glucose |
|
|
Term
| what regulates glycogen metabolis, how |
|
Definition
| glycogen synthase and phosphorlyase regulators, they have tissue specific isoenzymes |
|
|
Term
| what activates glycogen synthase in the liver |
|
Definition
| insulin, glucose-6-phosphate |
|
|
Term
| what inhibits glycogen synthase in the liver |
|
Definition
|
|
Term
| what activates glycogen synthase in the muscle |
|
Definition
|
|
Term
| what inhibits glycogen synthase in the muscle |
|
Definition
|
|
Term
| what activates glycogen phosphorlyase in the liver |
|
Definition
|
|
Term
| what inhibits glycogen phosphorlyase in the liver |
|
Definition
|
|
Term
| what activates glycogen phosphorlyase in the muscle |
|
Definition
|
|
Term
| what inhibits glycogen phosphorlyase in the muscle |
|
Definition
|
|
Term
| what causes von gierke's disease |
|
Definition
| glucose-6-phosphate deficiency |
|
|
Term
| what does von greike's cause |
|
Definition
| severe fastin hypoglycemia, lactic acidosis, hepatomeagly, hyperlipidemia, hyperuricemia, short stature due to growth retardation |
|
|
Term
| what does sever fasting hypoglycemia cause in von gierke's disease |
|
Definition
| cannot release glucose from liver from gluconeogenesis or glycogenolysis |
|
|
Term
| what does lactic acidoses cause in von gierke's disease |
|
Definition
| glucose-6-phosphate builds up an stops at gluconeogenesis, PDH is inhibited, lactate production is favored, lactate from RBC does not go to gluconeogenesis |
|
|
Term
| what does hepatomeagly cause in von gierke's disease |
|
Definition
| glycoen metabolites accumulate in liver and FA synthesis is favored, the liver swells because glycogen likes water |
|
|
Term
| what does hyperlipidemia cause in von gierke's disease |
|
Definition
| increased fa synthesis in liver due to deraged glucose in the liver |
|
|
Term
| what does hyperuricemia cause in von gierke's disease |
|
Definition
| glucose-6-phosphate build up tieing up cellular phosphate leading to turn over of nucleotides |
|
|
Term
| what causes pompe disease |
|
Definition
| lysosomal a1-4 glucosidase deficiency, hurts lysosomal glycogen degredation |
|
|
Term
| what are the symptoms of pompe disease |
|
Definition
| like other lysosomal storage disease, accumulation of the compound that cannot be broken down |
|
|
Term
|
Definition
| debranching enzyme deficiency |
|
|
Term
| what are the symptoms of cori disease |
|
Definition
| mild hypoglycemia, liver enlargement, short outer branches of glycogen |
|
|
Term
| why is there mild hypoglycemia in cori disease |
|
Definition
| glucose is only released from glycogen until a branch is reached |
|
|
Term
| why is there liver enlargement in cori disease |
|
Definition
| accumulation of glycogen remains |
|
|
Term
| what is deficient in anderson disease |
|
Definition
|
|
Term
| what are the symptoms of andersen disease |
|
Definition
| infantile hypotonia, cirrhosis, early death |
|
|
Term
| what is infantile hypotonia |
|
Definition
| few branches in glycogen so few ends release glycogen for muscle contraction |
|
|
Term
|
Definition
| linear glycogen is much less soluble and percipitates, damaging liver cells |
|
|
Term
| why is there early death in andersen disease |
|
Definition
| liver and heart are severly affected by percipitated glycogen |
|
|
Term
| what is deficnent in mcCardle disease |
|
Definition
| muscle glycogen phosphorlyase |
|
|
Term
| what are the symptoms of McCardle disease |
|
Definition
| muscle cramps, cannot release glycogen for muscle contraction, myoglobinuria |
|
|
Term
|
Definition
| destruction of some some muscle cells due to exercise induced lack of ATP |
|
|
Term
| what is wrong in Hers disease |
|
Definition
| liver gluycogen phosphorlyase deficneicy |
|
|
Term
| what are the symptoms of Hers disease |
|
Definition
| mild fasting mypoglycemia, hepatomeagly |
|
|
Term
| what occurs in mild fasting hypoglycemia |
|
Definition
| no glucose from glycogen but gluconeogenesis still is function |
|
|
Term
| why does hepatomeagly occur in glycogen storage diseases |
|
Definition
| excess build up of glycogen in the liver |
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