4 Glucokinase (hexokinase IV)Hexokinase I, II, or IIIAll hexokinase isozymes (I-IV)Answer Bankwill phosphorylate several hexoses including gluCosewhen blood glucose levels fall below normal range, isozyme remains at maximum velocityK is in the range of physiologic blood.glucose levelsplays an important-role in liver regulation of blood glucose levelsubcellular localization is regulated by fructose 6-phosphatewill be saturated by normal blood glucose concentrationsnot sensitive to inhibition by glucose 6-phosphalewhen blood glucose is low, will cause cells to trap.glucose by phosphorylation The presence of multiple hexokinase isozymes (I–IV) for the phosphorylation of glucose enables specific organs to regulatecarbohydrate metabolism in a unique way. Hexokinase IV, also called glucokinase, represented by the blue curve in the plot, isthe predominant isozyme in liver. Hexokinase IV has distinct kinetic properties from the other hexokinase isozymes, which arerepresented by the red curve. Note the difference in the shapes of the curves within the physiological range of glucoseconcentration (~4 to 6 mM).O.80.6glucokinase (hexokinase IV)0.402 -F8101214Glucose concentration (mM)Determine whether each phrase describes glucokinase, hexokinase isozymes I-III, or all hexokinase isozymes.Note: Assume that the kinetic behavior of hexokinase isozymes in vivo is similar to in vitro.Glucokinase (hexokinase IV)Hexokinase I, II, or IIIAll hexokinase isozymes (I-IV)

Isozymes are the enzymes with same catalytic activity but differ in efficiency and enzyme forms.…

Glucokinase (hexokinase IV) Hexokinase I, II, or III All hexokinase isozymes (I-IV) Answer Bank will phosphorylate several hexoses including glucose when blood glucose levels fall below normál range, isozyme remains at maximum velocity Km is in the range of physiologic blood glucose levels plays an important role in liver regulation of blood glucose level subcellular localization is regulated by fructose 6-phosphate will be saturated by normal blood glucose concentrations not sensitive to inhibition by glucose 6-phosphate when blood glucose is low, will cause cells to trap glucose by phosphorylation