Mitochondria & Chloroplast

Compare chloroplast and mitochondria

Chloroplast can only be found in plants, while mitochondria can be found in not only plants but also in animals. They have some similarities like: they both have double membrane and intermembrane space; Contain DNA and RNA, which are involved with the synthesis of the membrane and enzyme proteins, when the organelles replicate during cell division. Contain 70s ribosomes, and many similar enzymes and coenzymes. Both are involved in ATP production via a proton gradient (across the thylakoid membrane of chloroplast, across the cristae for mitochondria), ATP-synthatases appearing as stalked particles (on the thylakoid membrane of chloroplast, on the cristae of mitochondria). There are electron transport chains on the thylakoid membrane of chloroplast, on the cristae of mitochondria. Particularly they are self-replicate.

However, they are still different in their structures: Chloroplast is usually coloured as it contains thylakoid membranes and pigment molecules but a mitochondrium is hardly found in coloured because there is no pigment in it. The liquid part inside chloroplast is called “stroma” but in mitochondria is “matrix”.

Despite both being the main power supplies for organisms, each of them function differently.  Chloroplasts are involved in photosynthesis – they require energy from light to make sugar (glucose) (stored) from simpler substance through Calvin cycle. Mitochondria are involved in respiration – energy (ATP) is released by breaking down glucose - Complex substances (sugar) are broken down into simpler ones – through Krebs cycle.