Glucokinase differs from hexokinase in several impor- tant properties. For example, it has a much higher K m , requiring a higher glucose concentration for half-saturation (see Figure 8.13). Thus, glucokinase functions only when the intracellular concentration of glucose in the hepatocyte is elevated, such as during the brief period following consumption of a carbohy- drate-rich meal, when high levels of glucose are delivered to the liver via the portal vein. Glucokinase has a high V max , allow- ing the liver to effectively remove the flood of glucose delivered by the portal blood. This prevents large amounts of glucose from entering the systemic circulation following a carbohydrate- rich meal, and thus minimizes hyperglycemia during the absorptive period. [Note: GLUT-2 insures that blood glucose equilibrates rapidly across the membrane of the hepatocyte.]