Differences Between Hexokinase and Glucokinase

Differences Between Hexokinase and Glucokinase


Hexokinase Glucokinase

• The enzyme is non-specific, • The enzyme is specific, and
and can phosphorylate any of can phosphorylate glucose
the hexose. only
• More stable • Physiologically more labile

• Found almost in all tissues • Found only in liver

• Found in fetal and adult liver • Found in adult liver and not
in fetal liver
• The enzyme is allosterically • The enzyme is not inhibited
inhibited by glucose-6- by glucose-6-phosphate.
phosphate
• Km is low(0.1mM), hence • Km is high(10mM), low
high affinity for glucose affinity for glucose.
• Inhibited by glucocorticoids • Inhibited by glucocorticoids
and growth hormone. Insulin and growth hormone. Insulin
does not have any effect on stimulates the synthesis of
hexokinase glucokinase
• Main function is to make • Main function is to clear
available glucose to tissues glucose from blood after
for oxidation at lower blood meals and at blood levels
glucose levels greater than >100 mg/dl
• The level of the enzyme is • The level of the enzyme is
not influenced by diabetes or decreased in fasting and in
fasting diabetes.


~Arunsudha Raghubalan