Describe about the mitochondrial membranes

The composition of the two mitochondrial membranes is entirely different. The outer membrane is rich in lipids and contains nearly 50% of lipids, the rest being proteins. The inner membrane, on the other hand, is rich in proteins (80%) and has only 20% lipids. The outer mitochondrial membrane is permeable to most low molecular weight compounds, such as, ATP, ADP, NAD and other metabolites. The inner mitochondrial membrane, however, is impermeable to most of the metabolites, and these are transported into and out of the mitochondria by special protein carrier systems, called the transporter systems.