Lecture 27 - Glycogen Met. II Flashcards
(16 cards)
End product of glycogenolysis
Glucose-1-P
Enzymes of glycogenolysis
1) Glycogenphosphorylase (GP)
2) Glycogen debranching enzyme (cleaves a-1,6)
3) Phosphoglucomutase (moves 3 sugars)
Branch point of glycogen is what kind of bond?
a-1,6
Lengths of glycogen bound by what type of bond?
a-1,4
Cleaves glycogen to form a G-1-P
Glycogenphosphorylase
Removes 3 glucose molecules near the a-1,6 branch point and places them on non-reducing end of another chain
transferase
Co-factor used in glycogenphosphatase
Vitamin B6
Cleaves the a-1,6 bond and removes the G-1-P by that bond
a-1,6 debranching enzyme (AKA “a-1,6 glucosidase”)
Moves the glucose released by the a-1,6 debranching enzyme to another free end of glycogen.
transferase
Location of glucose-6-phosphatase
liver endoplasmic reticulum
Phosphoglucomutase
Converts G-1-P to G-6-P
Mutation to G-6-Pase in liver/kidney. Results in severe hypoglycemia, as glucose is not cleaved from glycogen. A. GSD II Pompe B. GSD V McArdle C. GSD IV Hers D. GSD I Von Gierke
D. GSD I Von Gierke
Mutation to muscle phosphorylase. Prevents the release of glucose from glycogen during heavy exercise, resulting in decreased muscle contraction. A. GSD II Pompe B. GSD V McArdle C. GSD IV Hers D. GSD I Von Gierke
B. GSD V McArdle
Mutation of liver phosphorylase. Causes severe hypoglycemia. Like Type I GSD, but mild. A. GSD II Pompe B. GSD V McArdle C. GSD IV Hers D. GSD I Von Gierke
C. GSD IV Hers
Mutation to alpha-1,4-glucosidase. Inability to cleave glycogen, causing severe hypoglycemia and increased glycogen stores. Usually fatal before 2 years of age. A. GSD II Pompe B. GSD V McArdle C. GSD IV Hers D. GSD I Von Gierke
A. GSD II Pompe
Deactivation of GS in the face of high glucose levels is accomplished via _____.
A. PFK
B. PKA
C. GSK
D. PP1
C. GSK (Addition of Pi to GS deactivates the enzyme, and stops glycogen synthesis)
