Figure 1 | Sugar metabolism. Glucose and fructose are dietary sugars.
Glucose is mainly metabolized by glycolysis and can be regulated through
feedback inhibition by ATP or citrate, which redirects glucose towards
storage as glycogen. In liver cells expressing the enzyme ketohexokinase
(KHK), fructose is metabolized to fatty acids, triglyceride head groups
(glycerol, not shown) and triglycerides — a biosynthetic pathway that
is not regulated by the ATP- or citrate-feedback mechanisms. Glucose
can also be converted into fructose through the polyol pathway, which
involves the action of the enzyme aldose reductase (AR). In the absence
of feedback inhibition, glucose metabolites can also be used to generate
fatty acids and triglycerides. PFK, phosphofructokinase.