Which of the following substances inhibits glycolysis?

Citrate is an important metabolic intermediate that plays a regulatory role in various biochemical pathways, including glycolysis. When citrate levels are high, it indicates that there is an abundance of energy and substrates available for the citric acid cycle, signaling to the cell that there is no immediate need to break down glucose for energy. As a result, citrate acts as an inhibitor of glycolysis by inhibiting phosphofructokinase-1 (PFK-1), which is a key regulatory enzyme in glycolysis.

When citrate binds to PFK-1, it reduces the enzyme's affinity for its substrate, fructose 6-phosphate, effectively slowing down the glycolytic pathway. This feedback mechanism helps the cell to regulate energy production based on its metabolic needs, ensuring that glucose is not unnecessarily metabolized when energy levels are sufficient.

In contrast, other substances like AMP and fructose 2,6-bisphosphate promote glycolysis. AMP acts as a signal of low energy status and activates PFK-1, while fructose 2,6-bisphosphate is a potent activator of PFK-1, pushing the glycolytic pathway forward. Insulin also stimulates glycolysis by promoting the uptake of glucose into cells and activating pathways