Most DNA is carried on the chromosomes. But an important form is found in the mitochondria of cells, which are structures that help provide energy.
Douglas Wallace of the Center for Molecular and Mitochondrial Medicine and Genetics at the University of California at Irvine and colleagues looked at the brains of 23 people who died of Alzheimer's and 40 people who died free of dementia.
reminds me of the mitochondrial Eve:
Although researchers named her after the Biblical Eve, mitochondrial Eve was not the sole living female of her day. Researchers believe as many as 20,000 individuals of Eve's species may have lived at the same time as her. But of the females of her day, only Eve produced an unbroken line of daughters that persists today. As a result, only Eve's mitochondria have descendants in the cells of living humans, and only from Eve do all living people descend along their maternal lines. (source)
so,uh... it looks to me like us as humans get our energy from our mothers