Which organelles are involved in photosynthesis and may support endosymbiotic theory?

Chloroplasts are the organelles primarily involved in photosynthesis, a process that converts light energy into chemical energy stored in glucose. These organelles contain chlorophyll, which captures sunlight, and other necessary enzymes and proteins that facilitate the conversion of carbon dioxide and water into sugars and oxygen.

The support for the endosymbiotic theory, which proposes that certain organelles originated from free-living prokaryotic organisms that were engulfed by ancestral eukaryotic cells, is particularly strong for chloroplasts. They contain their own DNA, which is circular and resembles bacterial DNA in structure, and they replicate independently of the cell through a process similar to binary fission. Additionally, chloroplasts have double membranes, which is consistent with the idea of an engulfed cell. This evolutionary perspective provides insight into the origin of complex eukaryotic cells and emphasizes the significance of chloroplasts in both photosynthesis and the broader context of cellular evolution.