Pentose Shunt and Fatty Acid Catabolism Old Exam Questions

The pentose shunt pathway has two phases. Correctly describe them:

Phase I: Reduction os NADP+

Phase II: Production of sugars with 3-7 carbon atoms

Correctly name the pentose shunt intermediates that are also intermediates in glycolysis:

Glucose-6-phosphate and Fructose-6-phosphate

A glycerol ester

What is the correct sequence in which cytoplasmic reactions prepare a fatty acid for transfer into the mitochondrion?

Formation of acylated-adenylate → formation of acyl-CoA → formation of acyl-carnitine

The first step in the beta-oxidation of fatty acids is oxidation of the beta carbon, catalyzed by acylated CoA dehydrogenase. What co-factor is required for this reaction?

FAD

Thiolysis, the last step in the fatty acid beta-oxidation cycle, produces a:

Shortened Acyl-CoA

Glycerol from breakdown of triacylglycerol is phosphorylated to glycerol 3-phosphate. What metabolite in glycolysis/gluconeogenesis is made directly from glycerol-3-phosphate?

Dihydrocyacetone phosphate

Glucagon and Epinephrine play important roles in the regulation of energy metabolism. Which statement about these are true?

Both epinephrine and glucagon stimulate lipolysis

In the initial phase of the pentose phosphate pathway, glucose-6-phosphate is converted into ribulose 5-phosphate. These reactions have two additional products. What are these?

NADPH and CO2

How many reducing equivalents are produced in the initial phase of the pentose phosphate pathway?

2

Phosphatidate

What is an important outcome of the pentose phosphate pathway?

Production of fructose-6-phosphate

1 = NADP+

2 = NADPH + H+

What factor regulates the rate of the pentose phosphate pathway?

Concentration of NADP+

Glyceraldehyde-3-phosphate is produced by the pentose phosphate pathway and is also an intermediate in _________.

glycolysis

The conversion of glucose-6-phosphate to ribulose-5-phosphate involves what molecule acting as an oxidant?

NADP+ acting as an oxidant

What term best describes the type of enzyme that catalyzes this reaction?

Epimerase

The regulation of the pentose phosphate pathway primarily occurs on what enzyme?

Glucose-6-phosphate dehydrogenase

How is the pentose phosphate pathway operated when the cells need more NADPH, but not the ribose 5-phosphate?

After oxidation phase of PPP, intermediates in the non-oxidative phase flux into gluconeogenesis to regenerate glucose-6-phosphate

2 and 4