Final answer:
Fructose is the monosaccharide that bypasses the regulatory step in glycolysis facilitated by phosphofructokinase, thus allowing for a faster metabolism of the sugar without the usual regulatory control.
Step-by-step explanation:
The monosaccharide that bypasses the major regulatory step in glycolysis, allowing for faster metabolism, is fructose. Specifically, fructose can be phosphorylated to fructose-1-phosphate by the enzyme fructokinase, bypassing the phosphofructokinase regulation point of glycolysis.
The regulatory steps in glycolysis are crucial for controlling the pathway's rate and are mainly focused on the enzymes hexokinase and phosphofructokinase. Hexokinase phosphorylates glucose to glucose-6-phosphate, a step that is regulated by the product of the reaction. The conversion of fructose-6-phosphate to fructose-1,6-bisphosphate, catalyzed by the enzyme phosphofructokinase, is considered the committed step and is highly regulated. However, when fructose enters the pathway as fructose-1-phosphate, it bypasses the tightly controlled phosphofructokinase step, entering the pathway downstream and potentially leading to an increased rate of glycolysis.