Fructose and glucose phosphorylating enzyme (PubMed:9014361). May be involved in the phosphorylation of glucose during the export from mitochondrion to cytosol (PubMed:9014361). Acts as sugar sensor which may regulate sugar-dependent gene repression or activation (PubMed:9014361). Mediates the effects of sugar on plant growth and development independently of its catalytic activity or the sugar metabolism (PubMed:9014361). May regulate the execution of program cell death in plant cells (PubMed:16920781). ATP + D-hexose = ADP + D-hexose 6-phosphate + H(+) ATP + D-fructose = ADP + D-fructose 6-phosphate + H(+) ATP + D-glucose = ADP + D-glucose 6-phosphate + H(+) Carbohydrate metabolism; hexose metabolism. Carbohydrate degradation; glycolysis; D-glyceraldehyde 3-phosphate and glycerone phosphate from D-glucose: step 1/4. A number of isoforms are produced. According to EST sequences. Highly expressed in siliques, at intermediate levels in roots and flowers, and at lower levels in stems, rosette and cauline leaves. Plants are overall smaller with a reduced number of flowers and siliques and display a glucose-insensitive phenotype which allows them to grow on high glucose concentration medium (>6% glucose). Belongs to the hexokinase family.