Fotoreceptor

Fotoreceptor is a term used to describe a cell or molecule that is sensitive to light. These specialized components play a crucial role in various biological processes, most notably in vision. In the eyes of animals, fotoreceptors are photoreceptor cells located in the retina. These cells convert light energy into electrical signals that are then transmitted to the brain, enabling sight. The two main types of photoreceptor cells are rods and cones. Rods are highly sensitive to low light conditions and are responsible for black and white vision, while cones are less sensitive to light but are responsible for color vision and function best in brighter light.

Beyond vision, fotoreceptors are also found in plants and bacteria. In plants, phototropins and cryptochromes are types of fotoreceptors that regulate growth and development in response to light, influencing processes like germination, flowering, and leaf movement. In microorganisms, fotoreceptors can be involved in phototaxis, the movement of an organism in response to light, allowing them to seek out optimal light conditions for photosynthesis or avoid harmful radiation. The molecular basis for fotoreception often involves a light-sensitive pigment, such as rhodopsin in animal eyes or phytochromes in plants, which undergoes a conformational change upon absorbing light, initiating a cascade of biochemical events.