Carbohydrate Metabolism — Flashcards

Flashcard 81: Hers disease is characterized by _____ gluconeogenesis and impaired glycogenolysis (impaired or functional)

Answer: functional

Flashcard 82: _____ disease is caused by a deficiency of the enzyme hepatic glycogen phosphorylase

Answer: Hers

Flashcard 83: _____ is converted to fructose via the enzyme sorbitol dehydrogenase

Answer: Sorbitol

Flashcard 84: Isomers that differ in configuration around only one specific carbon atom (with the exception of the carbonyl carbon) are defined as _____ of each other.

Answer: epimers

Flashcard 85: Glycogen phosphorylase is activated by _____ via the alpha-1 (liver only)

Answer: epinephrine

Extra: Epinephrine stimulates glycogenolysis in the liver through both α1 (Gq → IP3/DAG → Ca²⁺) and β2 (Gs → cAMP) receptors. In skeletal muscle, epinephrine acts via β2 receptors. The α1 receptor pathway for epinephrine-mediated glycogenolysis is specific to the liver. Additionally, glucagon stimulates glycogenolysis in the liver only (via Gs).

Flashcard 86: _____ is converted to fructose-1,6-bisphosphate via the enzyme phosphofructokinase-1 (PFK-1)

Answer: Fructose-6-phosphate

Flashcard 87: Deficiency of _____ or xylitol dehydrogenase necessary for xylitol metabolism results in Pentosuria

Answer: L-xylulose reductase

Flashcard 88: Which GAG is exclusively intracellular?_____

Answer: Heparin

Flashcard 89: What is the most potent allosteric activator of PFK-1?_____

Answer: Fructose 2,6 bisphosphate

Flashcard 90: _____ isomers differ in the orientation of the H and OH groups around the carbon atom adjacent to the terminal alcohol carbon

Answer: D and L isomers (Enantiomers)