In liver cells we have this same hexacionase that we also have in muscle cells. But in liver cells we have an important isozyme to this particular hexacinase. Now let's recall what an isozyme is. So two protein molecules that are different are said to be isozymes if they essentially catalyze that same, similar type of process. And the isozyme to the hexokinase that is found in liver cells but is not found in skeleton muscle cells, is glucokinase. So, unlike in skeleton muscle tissue, there is an isozyme to hexokinase present liver cells known as glucokinase.