https://en.wikipedia.org/wiki/Purple_sulfur_bacteria https://en.wikipedia.org/wiki/Purple_sulfur_bacteria, https://en.wikipedia.org/wiki/Bacteriorhodopsin https

https://en.wikipedia.org/wiki/Purple_sulfur_bacteria https://en.wikipedia.org/wiki/Purple_sulfur_bacteria, https://en.wikipedia.org/wiki/Bacteriorhodopsin https://en.wikipedia.org/wiki/Bacteriorhodopsin, and of course https://www.nobelprize.org/prizes/chemistry/1988/8787-the-first-crystals-of-membrane-proteins/ https://www.nobelprize.org/prizes/chemistry/1988/8787-the-fi...