Green and red are the colors of life: green for the chlorophyll in plants, red for the hemoglobin in blood cells of man and animal. That red-blooded human beings must eat green leaves, every housewife ...

A Universal Molecule of Living Matter The tetrapyrrole ring, a chemical structure made up of four smaller rings, occurs in the chlorophyll of plants, the hemoglobin of blood and many enzymes which, ...