Nick Lane’s book The Vital Question has a great discussion of endosymbiosis in terms of metabolism. The point of the book is that all metabolism is powered by a proton gradient. It becomes very inefficient to maintain that in a larger cell, so having smaller subcompartments within a larger cell where metabolism can take place (like mitochondria) is vital for getting bigger. (There are some giant bacteria, but they have unusual metabolic adaptations). I think he also discusses why mitochondria need to retain the key genes for metabolism—I think it’s to do with timely regulation.
Nick Lane’s book The Vital Question has a great discussion of endosymbiosis in terms of metabolism. The point of the book is that all metabolism is powered by a proton gradient. It becomes very inefficient to maintain that in a larger cell, so having smaller subcompartments within a larger cell where metabolism can take place (like mitochondria) is vital for getting bigger. (There are some giant bacteria, but they have unusual metabolic adaptations). I think he also discusses why mitochondria need to retain the key genes for metabolism—I think it’s to do with timely regulation.