Exam 12: Gluconeogenesis, the Pentose Phosphate Pathway, and Glycogen Metabolism

More energy in the form of ATP is required to synthesize glucose than can be obtained from it by glycolysis alone.

What types of reactions are involved in the two-step conversion of glucose to fructose?

Gluconeogenesis shares some, but not all, enzymes with the glycolytic pathway. It would appear to be more efficient if both pathways used all of the same enzymes since the pathways are essentially the reverses of each other. Why donʹt both pathways use all of the same enzymes?

Since caffeine inhibits cAMP phosphodiesterase, too much coffee can result in the synthesis of too much glycogen.

Epinephrine can stimulate glycogen degradation while at the same time, lowering glycogen synthesis.

In the Cori cycle, gluconeogenesis occurs in and glycolysis in .

The brain normally uses both glucose and fatty acids as energy sources.

Enzymes to regulate glycogen metabolism are always active when phosphorylated by protein kinases.

In ruminants, microorganisms produce propionate. The three-carbon acid must be converted to before entering the gluconeogenesis pathway.

Glycerol can supply electrons to the electron transport chain at the same time as it can be a precursor in gluconeogenesis.

Glucagon increases the transcription of the gene for phosphoenolpyruvate carboxykinase (PEPCK) in gluconeogenesis, while insulin decreases it.

Which is an intermediate formed in the conversion of glucose to fructose?

Protein kinase A, which stimulates glycogen degradation, is activated directly by

The enzyme transketolase transfers 2-carbon units from ketose phosphates to aldose phosphates.

Glycogenin is a protein scaffold for glycogen as well as an enzyme catalyzing extension of the glycogen primer.

The non-oxidative stage of the pentose phosphate pathway produces substances that are intermediates of .

The non-oxidative stage of the pentose phosphate pathway .

Glucose 1,6-bisphosphate is the primary starting substrate for the pentose phosphate pathway.

Fructose 2,6-bisphosphate is a modulator that can stimulate either glycolysis or gluconeogenesis, depending on cellular glucose concentrations.

The pentose phosphate pathway has two primary products. They are .