Light energy conversion in halobacterium halobium

✍ Scribed by Stoeckenius, Walther ;Lozier, Richard H.

• Book ID: 102438384
• Publisher: Wiley (John Wiley & Sons)
• Year: 1974
• Tongue: English
• Weight: 359 KB
• Volume: 2
• Category: Article
• ISSN: 0091-7419
• DOI: 10.1002/jss.400020519

✦ Synopsis

Abstract

Halobacterium halobium carries out photophosphorylation. A rhodopsin‐like protein, bacteriorhodopsin, located in the cell membrane mediates the first step in energy transduction, the conversion of light energy into a chemiosmotic gradient. After absorption of a photon, bacteriorhodopsin undergoes a series of fast reactions, returning to its original state in a few milliseconds. In continuous light it cycles continuously at 100 to 200 cps. During a cycle protons are taken up on the cytoplasmic side of the membrane and released on the outer surface, thus generating a chemiosmotic gradient which can drive phosphorylation of ADP to ATP.