You Are Examining the Biochemical Characteristics of the Liver Dysfunction

You are examining the biochemical characteristics of the liver dysfunction in your patient who is exhibiting signs of a GSD. You have isolated the microsomal fraction (contains the endoplasmic reticulum) of a liver biopsy homogenate from your patient and a control individual for your studies. Incubation with radioactive phosphate-labeled glucose 6-phosphate results in an increase in isotope associated with the microsomes from your control sample but no increase in association with the microsomes from your patient. These results are best explained by a defect in which of the following?

A) glucose-6-phosphatase activity in the microsomes
B) microsomal glucose-6-phosphate transporter
C) cytosolic glucose 6-phosphatase
D) microsomal glucose transporter
E) microsomal phosphate transporter