PSL300H1 Lecture Notes - Lecture 5: Color Vision, Chromoprotein, Chromophore
Document Summary
Photopigments undergo chemical changes when they absorb light. They are the non-protein, chromophore parts of chromoproteins (e. g. photoreceptor proteins), but medical writers often use the word to refer to the whole combined molecule ( rhodopsin is a photopigment ). Opsin sometimes means the non-chromophore part of a chromoprotein ( rhodopsin is opsin bound to retinal ), but sometimes it means the whole chromoprotein, so that rhodopsin is a kind of opsin. Different opsins (e. g. rhodopsin and cyanolabe) differ in a few amino acids. All human opsins bind (or include) the same chromophore: retinal, whose absorption depends on the protein it binds. In 2014 i said opsins consist of opsin proteins bound to a chromophore (retinal in humans), and that rhodopsin is an opsin, consisting of rhodopsin protein bound to retinal. N light has a wavelength:the distance from one wave peak to the next. The wavelengths we normally see range from 400 nm for violet to 700 nm for red.
