Tutorial
on protein architecture (written by Timothy Driscoll for Lehninger,
Nelson and Cox, 3rd. Edition. Requires the
Chime plugin and runs better with Netscape.)
Porphyrins are light-activated chemicals that can be used to combat ills including tumors and diseases of the eye. But they have a dark side: when the wrong forms of them build up in the body, they cause a disease called porphyria
Pigments that turn caustic on exposure to light can fight cancer, blindness and heart disease. Their light-induced toxicity may also help explain the origin of vampire tales
