Membrane-bound sacs in which digestion occurs are called
3. Cristae contain enzymes important to ATP production; cristae also increase the surface area for ATP production. e. Lysosomes are membrane-enclosed sacs that contain hydrolytic enzymes, which are important in intracellular digestion, the recycling of a cellâs organic materials and programmed cell death (apoptosis).Lysosomes carry out intracellular digestion in a variety of ways.. Cristae contain enzymes important to ATP production; cristae also increase the surface area for ATP production. e. Lysosomes are membrane-enclosed sacs that contain hydrolytic enzymes, which are important in intracellular digestion, the recycling of a cellâs organic materials and programmed cell death (apoptosis).