EPISODE PREVIEW
This program examines the complex code of human inheritance -- from the experiments of pioneer geneticist Gregor Mendel to the discoveries in today's sophisticated laboratories.
© 1974, British Broadcasting Company
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Handedness of Biomolecules (an explanation)
Bronowski mentions that Pasteur was fascinated by substances, such as crystals of tartrate, had left- and right-handed forms. He surmised that these properties reflected asymmetry -- handedness -- in the molecules making up these crystals.
(Many crystalline forms of substances reflect macroscopically (that is, big enough to see) the symmetry of their underlying molecules. See THIS, section A.)
He grew crystals of chemically synthesized tartrate, and found that he could separate left- and right-handed crystals under a microscope. When he made solutions of them separately, then crystallized them again, both forms maintained their asymmetry.
