ABSTRACT
This chapter discusses the approach of studying the origin of mitochondria from the eukaryotic angle, namely from the host side of the symbiosis. The transformation of free-living alphaproteobacteria into proto-mitochondria and their evolution into permanent organelles within eukaryotic cells is one major transition in evolution and therefore a fundamental subject of research and conjectures in biology. The mitochondrial organelle defines eukaryotic cells and thus it is at least as old as the first proto-eukaryotic organism, LECA Last Eukaryotic Common Ancestor. The structure, density and morphology of the cristae vary considerably in protists and algae with respect to the classical images of mitochondrial in mammalian cells. Cardiolipin and its metabolites have been traditionally considered to play a role in shaping the membrane curvature and consequently the morphology of mitochondrial cristae. The structure, density and morphology of the cristae vary considerably in protists and algae with respect to the classical images of mitochondrial in mammalian cells.
