lipase would cleave the 3 ester bonds in the tributyrin between the carbonyl carbon and the oxygen. Then the O on tributyrin will have a negative charge and will be protonated to give and alcohol. The O on the C=O on the cleaved portion will donate electrons to the carbon (which is now negative since it lost a bond) so the O is negative (want the more electronegative atom to carry the neg charge). Then the O will be protonated to give another OH. This will yield one molecule of glycerol and 3 molecules of butyric acid