So in this intermediate, once we transfer the group onto the enzyme, we transform A into product C. And now the product C can be released from that complex. And so now we have this modified complex E with the star on top. Now, next, the second substrate B goes and binds into the active side of that enzyme to form this intermediate. And now that group that was transferred by A into the active side of E is transferred onto that molecule B and that transforms the second substrate B into the product D. And finally, this intermediate in this intermediate D is released from that enzyme and that reforms our original enzyme. So notice in this reaction, like in any enzyme catalyze reaction, even though the enzyme might be modified intermediately at the end, that enzyme is produced and exists in its original, unchanged form. So the defining property of this reaction is that the first substrate is converted to the product and then released before the second substrate binds to the active side of the enzyme.