Both the membranes of mitochondrion are

The mitochondrion is a double membrane-bound organelle found in most eukaryotic cells. It contains outer and inner membranes composed of phospholipid bilayers and proteins. The two membranes have different properties. Because of this double-membrane organization, there are five distinct parts to a mitochondrion- the outer mitochondrial membrane, the intermembrane space (the space between the outer and inner membranes), the inner mitochondrial membrane, the cristae space (formed by infolding's of the inner membrane), and the matrix (space within the inner membrane). Mitochondria are also called as the power house of the cell.