ABSTRACT

Think of the intense red of blood, and you are thinking of one of the most visually striking groups of pigments in nature. Heme and its related chrom pohores provide some of the most intense natural pigments known and are distributed far more widely than we m ight suppose. Probably every living organism has the ability to synthesize heme, and many utilize the light-absorbing properties of its derivatives to their own ends. Perhaps the greatest quantities of hem e-related pigments on the planet are in our lakes and oceans, where they are used by algae as light-harvesting and reaction center pigments in photosynthesis.