Q4. The enzymes hexokinase and glucokinase both act on glucose as substrate. The Km of hexokinase for glucose is 30M, whilst the Km of glucokinase for glucose is 10mM. Which one of the following statements regarding hexokinase, glucokinase, or both enzymes are true when the blood glucose concentration is 10mM as may be found in the hepatic portal vein following a high carbohydrate meal)? A. Both hexokinase and glucokinase are operating at near their maximum velocity B. Hexokinase is operating at near to its maximum velocity C. Glucokinase is operating at near to its maximum velocity D. Hexokinase is operating at a negligibly low rate E. Neither hexokinase nor glucokinase is operating at near to its maximum velocity