<span>The two
membranes of the mitochondria and the inner and outer membranes of the
chloroplast have similar functions. The external membrane of the mitochondria
serves as covering of the organelle to protect it; while the internal lining
which is folded repeatedly in layers contains proteins. Likewise, the
chloroplast has inner and outer membranes too that contain and protect its
different parts such as the stroma and thylakoids.</span>
