1. What is happening in a healthy individual about an hour into a glucose tolerance test? (Note: At this early time-point, blood glucose levels are still high. Also, remember that a person who is taking a glucose tolerance test was fasting for 12 hours prior to the test!) (Select ALL that apply!) Hint: Review pages 319-325, 462-467 and 489-491 of Tymoczko 3E before attempting this question.

A. Glucose is being exported by the liver

B. Glucose is being taken up by the liver

C. Glycogen is being synthesized by adipocytes

D. Glycogen is being synthesized by the liver

E. Glucose is being taken up by muscle cells that are deficient in glycogen

F. Glycogen is being synthesized in any muscle cells where it is depleted

Glucose is being taken up by the brain

Large amounts of glycogen are being synthesized by the brain

2. In a healthy individual, glucose concentrations will spike but then return to normal levels during a glucose tolerance test. In a type 1 diabetic, they will spike dramatically, due to a lack of insulin release and remain high. In a type 2 diabetic, they will also spike dramatically, but due to a lack of insulin response (reduced sensitivity to insulin) and remain high. (Hint: Review pages 466-467 of Tymoczko 3E for more information about type 1 and type 2 diabetes mellitus). Jessie had normal glucose levels throughout the glucose tolerance test except that she was more hypoglycemic than normal at the beginning and the end of the test. Which of the following could explain her test results? (Select ALL that apply!)

A. Jessie is a type 1 diabetic

B. Jessie is a type 2 diabetic

C. Jessie may have a problem with gluconeogenesis in the liver resulting in lower than normal glucose production during fasting

D. Jessie may have a problem with the production of ATP from other sources, i.e., β-oxidation of fatty acids, which results in increased glucose uptake by tissues from the blood to compensate

E. Jessie may have glucagon levels that are too high when fasting

F. Jessie may have glucagon levels that are too low when fasting

3. Consider how the carbon from fatty acids is ultimately converted into ketone bodies (Sections 27.1-27.3 of Tymoczko 3E). The build-up of FAs and the lack of significant ketone body formation could be explained by a deficiency in only a single biochemical pathway. What is it?

Glycolysis

Gluconeogenesis

The reactions catalyzed by the PDH complex

The citric acid cycle

β-oxidation

The pentose phosphate pathway

4. In what organ or tissue are fatty acids broken down into acetyl-CoA to be turned into ketone bodies?

The brain

Adipose tissue

Muscle

The liver

The skin

The pancreas