what is the difference/similarity between nad and nadp? what is the difference/similarity between nad and nadp? both transport electrons to the electron transport chain found on the inner mitochondrial membrane, but nadp transfers its electrons to the etc at a higher energy level. nad functions as an electron carrier, whereas nadp does not. nad functions as a free-energy source for cells, whereas nadp does not. both function as electron carriers, but nadp has a phosphate group and nad does not.