Biochemistry: USMLE Q No. 7

[Cardiac Arrest]

A 30-year-old healthy woman is undergoing an oral glucose tolerance test. After a catheter is inserted into an arm vein, she is given a drink containing 75 g of glucose. A blood sample is taken every 20 minutes and assayed for glucose and insulin concentrations. Twenty minutes after she drinks the glucose solution, which of the following biochemical findings would be expected?

A. Fatty acids in adipose tissue are mobilized
B. Hepatic glycogen synthesis is activated
C. Hepatic glycolysis is stimulated
D. Hepatic ketone synthesis is increased
E. Kidney gluconeogenesis is stimulated

[H@SSOOM]

Helloo

Insulin function is to facilitate glucose movement to the cytoplasm.
this woman is healthy till now (not DM) and she is doing a test, so her respose is expected to be normal: insulin will enhance glucose movement to the cells and increase glycolysis which is glucose breakdawn

I will choose

C. Hepatic glycolysis is stimulated

[Cardiac Arrest]

Option B (Hepatic glycogen synthesis is activated) is correct. Hepatic glycogen synthesis is activated by elevated concentrations of glucose-6-phosphate. Glucose-6-phosphate is converted via a series of reactions to glycogen.

Option A (Fatty acids in adipose tissue are mobilized) is incorrect. Fatty acids are mobilized in the fasting state when glucose concentrations are low.

Option C (Hepatic glycolysis is stimulated) is incorrect. Hepatic glycolysis is inhibited, rather than stimulated.

Option D (Hepatic ketone synthesis is increased) is incorrect. Hepatic synthesis of ketones is decreased, rather than increased. Ketone body synthesis is increased in fasting and starvation.

Option E (Kidney gluconeogenesis is stimulated) is incorrect. Gluconeogenesis in kidneys is inhibited, rather than stimulated. Gluconeogenesis is essential for maintaining blood glucose concentrations during fasting and, to a lesser extent, starvation.

[H@SSOOM]

very coooool. now I agree with your explanations.
The liver has its unique biochemical system.........
I lost my basic sciences, thanx dear brother for the Alarm

[oonr52]

Thanks God I chosed B :)

but I have a Q..
When we would expect that Insulin level should rise..
is it at the time of Sugar injection or after a little while or sth. else ???