fotopigmentek

Fotopigmentek are light-absorbing molecules found in many organisms that participate in the capture of light for vision, photosynthesis, or light sensing. They are typically chromophores bound to proteins, which tune their light absorption properties and trigger downstream chemical or signaling reactions when they absorb photons. Fotopigmentek are essential for translating light into biological information or energy.

In animals, visual photopigments include rhodopsin in rods and cone opsins in cone cells. These pigments consist of an opsin protein bound to retinal, a derivative of vitamin A. Absorption of photons causes retinal to change shape, activating the opsin and initiating a signaling cascade that ultimately yields visual information. The different cone pigments enable color discrimination by absorbing light at various wavelengths.

Photosynthetic organisms rely on a broader set of fotopigmentek. Chlorophylls (a, b, and related variants) and carotenoids absorb light and transfer excitation energy to reaction centers that drive electron transport and the synthesis of ATP and NADPH. Phycobilins, porphyrin-like pigments in cyanobacteria and red algae, extend light capture into different spectral regions. Plant and bacterial phytochromes, cryptochromes, and phototropins are light-sensing proteins that regulate development and behavior in response to red, far-red, or blue light. Bacteriochlorophylls serve similar roles in various photosynthetic bacteria.

The term fotopigmentek encompasses pigment molecules involved in vision, photosynthesis, and photoreception. Understanding their structure and photochemistry informs fields from biology and ecology to biophysics and optogenetics.