A medical student has been studying for exams and neglects to eat anything for 12 hours. At this point, the student opens a large bag of pretzels and eats every one of them in a short period. Which one of the following effects will this meal have on the student's metabolic state?
After a meal of carbohydrates (the major ingredient of pretzels), glycogen is stored in the liver and in muscle, and triacylglycerols are stored in adipose tissue. Owing to the rise in glucose level in the blood (from the carbohydrates in the pretzels), insulin is released from the pancreas, and the level of glucagon in the blood decreases. Because blood glucose levels have increased, there is no longer a need for the liver to synthesize glucose, and gluconeogenesis decreases. The change in insulin to glucagon ratio also inhibits the breakdown of triacylglycerols and favors their synthesis. The brain oxidizes glucose to CO2 andH2 O, whereas the red blood cells produce lactate from glucose because red blood cells cannot carry out aerobic metabolism.
Liver glycogen stores will be replenished.
The rate of gluconeogenesis will be increased.
The rate at which fatty acids are converted to adipose triacylglycerols will be reduced.
Blood glucagon levels will increase.
Nutrition & Digestion