Rhodopsin

Definition

Rhodopsin is a light-sensitive receptor protein found in the rod cells of the retina. It plays a critical role in converting light into electrical signals that can be interpreted by the brain.

5 Must Know Facts For Your Next Test

1. Rhodopsin consists of opsin and retinal, a derivative of vitamin A.
2. It is responsible for the initial step in the perception of light, particularly in low-light conditions.
3. When rhodopsin absorbs light, it undergoes a conformational change called photobleaching.
4. The regeneration of rhodopsin from its bleached form requires enzymatic reactions involving retinal and opsin.
5. Mutations in the rhodopsin gene can lead to retinal diseases such as retinitis pigmentosa.

Review Questions

• What are the two main components that make up rhodopsin?
• How does rhodopsin contribute to vision in low-light conditions?
• What is photobleaching and why is it significant for rhodopsin function?

Related terms

Opsin: The protein component of rhodopsin that binds to retinal.

Retinal: A derivative of vitamin A that acts as a chromophore within rhodopsin.

Rod Cells: Photoreceptor cells in the retina responsible for vision at low light levels.