Step-by-step explanation:
a) Inner membrane; in the form of ATP
The inner membrane of the mitochondria creates more space for cellular respiration. It has folds called cristae, which increase its surface area and provide more room for the chemical reactions involved in producing energy.
As for the form in which energy is stored, the mitochondria store energy in the form of ATP (adenosine triphosphate). ATP is a molecule that carries and provides energy for cellular processes.