Question

Which of the following statements accurately describe(s) how fructose metabolism in the liver differs from glucose metabolism? Select all that apply

1. In fructose metabolism, the phosphofructokinase reaction is bypassed, and glycolysis can proceed regardless of need.
2. The presence of fructose inhibits the entrance of glucose into glycolysis.
3. The major control point in both glucose and fructose metabolism is the reaction catalyzed by phosphofructokinase.
4. The fructose 1-phosphate pathway can deplete intracellular phosphate/ATP.

Answer 1

Statements 1, 2, and 4 accurately describe how fructose metabolism in the liver differs from glucose metabolism.

Step-by-step explanation:

In fructose metabolism, the phosphofructokinase reaction is bypassed, allowing glycolysis to proceed regardless of need. This can lead to the formation of large amounts of ATP and NADH. The presence of fructose also inhibits the entrance of glucose into glycolysis, resulting in less efficient energy production. Finally, the fructose 1-phosphate pathway can deplete intracellular phosphate and ATP, potentially leading to energy depletion.

Statement 3 is not accurate. The major control point in glucose metabolism is the reaction catalyzed by hexokinase, while the major control point in fructose metabolism is the reaction catalyzed by fructokinase. These reactions are not the same as the reaction catalyzed by phosphofructokinase.