n nHexokinase: Its function is to make sure there is enough glc for the tissues, even in the presence of low blood glc concentrations, by phosphorylating all the glc concentration gradient between the blood and the intracellular environment.
n nGlucokinase: Its function is to remove glc from the blood following a meal. n n(Hexokinase, Phosphofructokinase and pyruvate kinase, are 3 regulatory enzymes of glycolysis.) nLiver has an additional enzyme, glucokinase, that phosphorylate only glc
n n1. Glucokinase has a high Km because it phosphorylates glc only when its concentration is high. This occurs during the brief period after consumption of a carbohydrate rich meal, when high glc are delivered by portal vein.
n n2. Glucokinase has a high Vmax, allowing the liver to remove effectively this flood of glc from the portal blood. So this prevents extreme hyperglycemia after meals.
n
Enzymes like hexokinase and glucokinase facilitate the movement of sugar molecules by catalyzing their conversion to phosphorylated intermediates. These phosphorylated sugars are more reactive and can be easily transported across cell membranes to be utilized in various metabolic pathways.
glucokinase
Hexokinase is an enzyme involved in the phosphorylation of hexose (five carbon sugar). It speeds the process on adding a phosphorus to the sugar.
Glucokinase is often referred to as the 'glucose sensor' as it directly relates the rate of β-cell glucose-dependent insulin secretion and the rate of hepatocyte glucose metabolism to the ambient blood glucose level. Read more in related link below.
Hexokinase
Glucokinase
Hexokinase
It is not inducible by insulin
The conversion of glucose to glucose 6-phosphate catalyzed by hexokinase/glucokinase is an irreversible reaction that traps glucose within the cell. This process consumes one molecule of ATP and requires Mg2+ as a cofactor. Hexokinase has a high affinity for glucose and is present in most tissues, while glucokinase is found primarily in the liver and pancreas with a lower affinity for glucose.
Glucose is the substrate that is converted into glucose 6-phosphate by the enzyme hexokinase. Hexokinase catalyzes the phosphorylation of glucose to glucose 6-phosphate in the first step of glycolysis.
Some abbreviations for enzymes involved in the breakdown of glucose are HK (hexokinase), GK (glucokinase), PFK (phosphofructokinase), PK (pyruvate kinase), and G6Pase (glucose-6-phosphatase).
Glucokinase Regulatory Protein is found in the nucleus which binds glucokinase to inactive it
Enzymes like hexokinase and glucokinase facilitate the movement of sugar molecules by catalyzing their conversion to phosphorylated intermediates. These phosphorylated sugars are more reactive and can be easily transported across cell membranes to be utilized in various metabolic pathways.
in the cytosol
glucokinase. glucokinase has a high km(low affinity for glucose) so glucokinase only phosphorylates glucose when blood glucose is high, such as after a meal. As such, it makes sense that this would be sensor for B-cells
The conversion of glyceraldehyde 3 phosphate to 1, 3 bisphosphoglycerate catalyzed byglyceraldehyde 3 phosphate dehydrogenase using NAD+ and Pi
glucokinase