Bacteriorhodopsin

Definition

Bacteriorhodopsin is a protein found in the cell membrane of certain archaea, particularly Halobacterium. It functions as a light-driven proton pump, converting light energy into chemical energy.

5 Must Know Facts For Your Next Test

1. Bacteriorhodopsin is primarily found in the archaeon Halobacterium salinarum.
2. It operates by absorbing light and using that energy to transport protons (H+) across the cell membrane.
3. The protein contains retinal, a molecule that changes shape when it absorbs light, facilitating proton pumping.
4. This proton gradient created by bacteriorhodopsin is used to produce ATP through chemiosmosis.
5. Bacteriorhodopsin's ability to harness light energy is an example of phototrophy in archaea.

Review Questions

• Which organism is most commonly associated with bacteriorhodopsin?
• What type of molecule does bacteriorhodopsin contain that allows it to absorb light?
• How does bacteriorhodopsin contribute to ATP production?

Related terms

Halobacterium:

A genus of archaea known for living in high-salt environments and containing bacteriorhodopsin.

Retinal: A molecule bound to bacteriorhodopsin that changes conformation upon absorbing light.

Chemiosmosis:

The process by which ATP is produced using the energy from a proton gradient across a membrane.