You are examining the regulatory control of glycolysis by addition of a novel compound to a hepatocyte cell culture system. You discover that addition of the compound results in a decreased rate of ATP production from glucose while simultaneously increasing glucose output into the culture medium. Further studies demonstrate that the changes observed in your culture system with addition of the compound can be mimicked by altering the cytosolic levels of citrate. Your compound is most likely altering the rate of glycolysis
By which of the following mechanisms?

Question

Quizplus · Accepted Answer

Citrate is a known allosteric inhibitor of 6-phosphofructo-1-kinase (PFK1), a key regulatory enzyme in glycolysis. The compound likely mimics this effect, reducing glycolysis and ATP production while increasing glucose output.  Citrate, present in the cytosol, serves as a signal for a high-energy charge and inhibition of the TCA cycle. Under these conditions the rate of glucose oxidation via glycolysis needs to be reduced. Citrate serves as an allosteric inhibitor of the rate-limiting enzyme of glycolysis, PFK1.

You Are Examining the Regulatory Control of Glycolysis by Addition