Now suppose that light in the yellow range of wavelengths (approximately 577 nm to 597 nm) enters the eye and strikes the retina. Light with these wavelengths would activate both the green and the red cones of the retina.
Brewer's yeast. Uses. Brewer's yeast is traditionally used as a source of vitamin B, selenium, and chromium, especially by vegetarians. Clinical trials have evaluated yeast for a role in immunomodulation, respiratory infections, prevention of postsurgical infections (as beta-glucan), and as a source of dietary fiber to improve the lipid profile.
The most important ingredient in brewing was the last one discovered, because yeast is a single-celled organism that is invisible to the naked eye. Still, brewers have long known that some unseen agent turned a sweet liquid into beer. Modern brewers usually brew with purified strains of yeast that give exactly the result they want.