In prokaryotic cells, essential infoldings of the plasma membrane towards the cytoplasm are called mesosome. They can be in the form of the vesicles, tubules, and lamellae.
These help in (a) Cell wall formation, (b) DNA replication and distribution to daughter cells, (c) Respiration (analogous to mitochondria), (d) secretion of processes (to increase the surface area of the plasma membrane and enzymatic content).
They also help in the respiration and secretion process to increase the plasma membrane's surface area and enzymatic content. Mesosome is found in gram-positive bacteria. There are other membranous extensions in some photosynthetic prokaryotes like cyanobacteria and purple bacteria into the cytoplasm called chromatophores, containing pigments.
These are stacks of flat cavities membrane-bound, which together called the Golgi apparatus. It is a membrane-bound cell organelle having digestive enzymes. It is a type of peroxisomes that are found in the germinating seeds fat storage tissue.