What is the role of fructose-2,6-bisphosphate in glycolysis?

Question

How does this intermediate effect glycolysis if it is not a direct compound in it?

Answer 1

Basically, phosphofructokinase is the so-called "pacemaker" of cellular respiration. it is inhibited by ATP and therefore is a controlling factor in cellular respiration through feedback inhibition. This is about all you would need to know for AP BIO although certainly a more complicated step wise process would be required at higher levels.

Answer 2

Fructose-2,6-bisphosphate (Fru-2,6-P2) is a small molecule that plays an important role in regulating the breakdown of glucose (glycolysis) in cells. Specifically, Fru-2,6-P2 acts as an allosteric activator of the enzyme 6-phosphofructo-2-kinase (PFK-2), which is responsible for catalyzing the conversion of fructose-6-phosphate (Fru-6-P) to fructose-1,6-bisphosphate (Fru-1,6-P2) during glycolysis.

When the concentration of Fru-2,6-P2 is high, it binds to PFK-2 and causes it to become more active, leading to an increase in the conversion of Fru-6-P to Fru-1,6-P2. This, in turn, increases the rate of glycolysis and the production of ATP (adenosine triphosphate), which is the primary source of energy for cells.

On the other hand, when the concentration of Fru-2,6-P2 is low, it has less of an activating effect on PFK-2 and the rate of glycolysis slows down. This allows cells to adjust their energy production to meet their needs and helps to prevent the build-up of excess ATP, which can be toxic to cells.

Overall, the role of Fru-2,6-P2 in glycolysis is to help regulate the breakdown of glucose and the production of ATP, ensuring that cells have a steady supply of energy to meet their needs.

Answer 3

Fructose 2, 6 bisphosphate (F26BP) is a compound made outside of glycolysis. The intermediate is a regulator of the enzyme: phosphofructokinase-1 (PFK1) in the second step of glycolysis. F26BP is created by the enzyme phosphofructokinase-2 (PFK2) and can be broken back down to Fructose 6 Phosphate (F6P) by the enzyme Fructose 2, 6 Bisphosphotase (F26Bpase). When the enzyme PFK2 is activated, that causes for more F26BP to be made. In return, this signals the enzyme PFK1 to be activated thus allowing the body to do glycolysis! However, when the reverse enzyme of F26Bpase is activated, then we are breaking down F26BP and creating the reactant: F6P. In return, this would tell us to NOT do glycolysis because we are not activating PFK1 since we are not making F26BP. There are other modulators such as insulin and glucagon that also affect this process but ultimately, if the enzyme PFK2 is activated, more F26BP is made thus activating PFK1 to progress with glycolysis.