Structure a is there is a lipid bilayer of the mitochondrial membrane. it separates the intermembrane space and mitochondrial matrix. there are structures integrated into the membrane. structure a is a bulb-like structure with a port connecting the intermembrane space and mitochondrial matrix. structure a is there is a lipid bilayer of the mitochondrial membrane. it separates the intermembrane space and mitochondrial matrix. there are structures integrated into the membrane. structure a is a bulb-like structure with a port connecting the intermembrane space and mitochondrial matrix. atp synthase sensory protein an electron acceptor an electron donor phospholipid