Term
|
Definition
-glucose polymer
-storage carb in animals
-branched
-alpha 1-4 straight
-alpha 1-6 branches
-branches every 8-10 residues
-stores in liver, skeletal muscle, kidney |
|
|
Term
|
Definition
-conversion of free glucose to glucose-6-phosphate
-enzyme-hexokinase or glucokinase
-requires ATP
-conversion of G-6-P to G-1-P
-enzyme phosphoglucomutase |
|
|
Term
|
Definition
-synthesis of UDP-glucose
-glucose needs to be activated to add it to glycogen
-enzyme-UDP-glucose pyrophosphorylase
-pyrophosphate (PPi) is product
-broken down by pyrophosphatase |
|
|
Term
|
Definition
-synthesis of glycogen "primer"
-if glycogen stores are not completely depleted , UDP-glucose can add to current glycogen molecules
-if depleted use glycogenin as an acceptor for first UDP-glucose
-UDP-glucose reacts with OH of Tyr residue on glycogenin
-glycogenin auto catalyzes first few additions (1-4 linkages) |
|
|
Term
|
Definition
-elongation of glycogen chains
-enzyme-glycogen synthase
-transfer of glucose from UDP-glucose to the growing end of the chain (nonreducing end)
-C1 of UDP-glucose and C4 of accepting residue
-alpha 1-4 glycosidic bond |
|
|
Term
|
Definition
-formation of alpha 1-6 branches
-enzyme-4:6 transferase
-breaks every 6-8 glycosyl residues (alpha 1-4 bond)
-reattaches it to a nonterminal residue by alpha 1-6 bond
-both nonreducing ends can be elongated by glycogen synthase
-increases number of nonreducing ends
-can be synthesized and degraded faster |
|
|
Term
|
Definition
-not a reversal of synthesis
-mobilizes stored glycogen quick |
|
|
Term
|
Definition
-shortening of glycogen chains
-enzyme-glycogen phosphorylase
-cleaves alpha 1-4 linkages until 4 residues from a branch (limit dextrin)
-results in release of G-1-P |
|
|
Term
|
Definition
-removal of alpha 1-6 branches
-enzyme-debranching enzyme (2 activites)
-4:4 transferase-transfers 3 of 4 remaining glycosyl residues to another nonreducing end
-1:6 glucosidase-hydrolytic cleavage of alpha 1-6 bond, releasing free glucose |
|
|
Term
|
Definition
-conversion of G-1-P to G-6-P (for use in cells)
-enzyme-phosphoglucomutase
-reverse of glycogenesis rxn
-G-6-P to glucose
-enzyme glucose-6-phospatase |
|
|
Term
|
Definition
-glycogenesis-active in liver during high BG
-active in muscle during periods of rest |
|
|
Term
|
Definition
-glucagon-activates glycogenolysis
-insulin-activates glycogenesis |
|
|
Term
|
Definition
-glycogenesis-glycogen synthase is activated by substrate G6P
-glycogenolysis-glycogen phosphorylase is inhibited by G6P, glucose, and ATP |
|
|
Term
|
Definition
-glycogen storage diseases
-Pompe,McArdle,Cori Diseasec
-defects in enzymes, abnormal glycogen structure |
|
|
Term
|
Definition
-cleaves 1-4 links until 4 residues from each branch (limit dextrin)
-releases G-1-P |
|
|
Term
|
Definition
| -transfers 3 residues to another non reducing end |
|
|
Term
|
Definition
| -hydrolyitic cleavage of 1-6 bond releasing glucose |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
