Word: pigment
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Wald explained the well-known observation that animals and men deprived of vitamin A become night-blind, by demonstrating that the light-sensitive pigment of most rods participates directly in a retinal cycle with vitamin...
From the rods of fresh-water fishes, he extracted the vitamin-nature of the substance now called vitamin A-2. From chicken retina he obtained the first light-sensitive pigment to be found in these structures...
...example, Hooton found nine features characteristic of robbers-such things as attached ear lobes, heavy beards, diffused pigment in the iris. In a group of 414 robbers, six had none of these characteristics at all, no robber had all nine, and only one had as many as seven. But more than half had two or three of the features, which was a significantly higher incidence than in other criminal classes or in law-abiding people...
...British journal Nature fortnight ago, Dr. Svedberg reported experiments on molecules of hemocyanin (molecular weight, 6,740,000 units), a blue pigment from the blood of mollusks. He and his co-workers at the University of Upsala bombarded the hemocyanin particles with quanta of energy in the form of ultraviolet light. Certain wave lengths of the bombarding radiation split the blood pigment molecules into halves. This was like splitting inorganic atoms in a high-voltage atom-smasher...
...Primary protein reactions," declared Dr. Svedberg, "are . . . elementary acts which must, of necessity, obey the laws of quantum mechanics." The implications of this statement are vastly more important to science than the actual splitting of blood pigment molecules. If the quantization of biological processes can be continued far enough, it will be possible to explain in exact mathematical terms-in terms of atomic energy levels and electronspins-what happens when insulin is secreted in the pancreas, when starch is broken down in the digestive system, when an ovum is penetrated and fertilized by a spermatozoon, many & many a complex biological...