Is the eyespot a natural biosensor? observed from the perspective of a photoelectric sensor

that they capture the direction of light intensity and redirect it towards a photoreceptor, which consists of a multilayer membrane structure of photoreceptor protein that, when photo activated, produces an electrical charge similar to nerve impulses in visual processes:2 This charge determines the flagellar movement of the alga therefore its location in the water column in the optimal illumination area. Barsanti et al.,3 define this ocular-photoreceptor-flagella stain configuration as a simple but complete visual system. What makes this system analogous to other types of more complex vision is the presence of this photoreceptor protein, “Rhodopsin”, which consists of a protein part called opsin organized in 7 transmembrane helices and a lightabsorbing group, the retinal (eg the chromophore).4 This protein is very widely distributed in prokaryotes, eukaryotic algae,4 humans and other invertebrate animals5 and is responsible for converting photons into chemical signals that additionally stimulate biological processes in the nervous system of the latter two. In this case, the brain is the organ capable of translating these electrical signals into optical signals generating vision, because that is where all the images obtained that travel to different parts of it in the form of electrical impulses are generated6 and although microorganisms do not possess this specialized organ, we can not deny the fact that they possess all the machinery necessary to generate a vision similar to animals.