As you already know, clotoplaspos and mitochondria have internal and external members. As everything in nature is done in a functional way, the internal membranes are extremely important in the functioning of these two molecules.
In mitochondria, the internal membranes are responsible for delimiting the mitochondrial matrix, which is a fluid that contains enzymes, DNA, RNA and ribosomes.
In chloroplasts, the inner membrane is also responsible for delimiting a fluid that contains all the molecules and ions that are needed inside and outside the chloroplast.