Compare and contrast the structures and functions of mitochondria and chloroplasts.

Both mitochondria and chloroplasts are double-membraned organelles involved in energy conversion and contain their own DNA and ribosomes. However, mitochondria are found in nearly all eukaryotic cells and are responsible for cellular respiration, breaking down glucose to produce ATP. Chloroplasts are found only in plant cells and some protists, and they are responsible for photosynthesis, converting light energy into chemical energy (glucose). Structurally, chloroplasts contain stacks of thylakoids called grana, while mitochondria have inner folds called cristae.