Contrasting the Cellular Abilities of Eukaryotes and Prokaryotes

Abstract

The techniques of physiology, molecular biology, and ultrastructural cytology have led to an understanding of the functions and many mechanisms of action of eukaryotic cells and their parts. While typical prokaryotes contain no membrane-bound organelles, the typical eukaryotic cell contains two types of organelles. One class of organelles, those derived from ex-prokaryotes, the endosymbionts, includes mitochondria, chloroplasts, and (possibly) flagella. The other class is composed of extensions of the cell membrane: the nuclear membrane, the endoplasmic reticulum, the Golgi apparatus, lysosomes, peroxisomes, vacuoles, and other inclusion bodies. Actually some prokaryotes do have invagination of their cytoplasmic membrane, called mesosomes. Some mesosomes are artifacts, but some are regions with enhanced numbers of membrane proteins needed for photosynthesis and chemoautotrophy. These are the analogues of the second class of eukaryotic organelles.