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No. 117: May-June 1998

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Terrestrial Life Is Ambidextrous

But only slightly so!

In SF#115, we asked whether right-handed organic molecules can be found in any terrestrial life forms. E. Clark answered as follows:

"D-amino acids [right-handed amino acids] do occur fairly often in bacterial cell walls and other microbial products such as antibiotics. When I was first introduced to this fact, I was intrigued and I wondered if the presence of D-amino acids in these large molecules might indicate that there was something special about the way they were synthesized -- perhaps, for example, that they essentially assembled themselves without the need of individual synthetic enzymes at each synthetic step."

(Clark, Ed; personal communication, February 28, 1998.)

Comment. So, right-handed molecules are not forbidden on earth, but we are still faced with that great preponderance of left-handed molecules. What "force" is at work here, or is this just the way things are? We should not settle for the latter interpretation.

From Science Frontiers #117, MAY-JUN 1998. 1998-2000 William R. Corliss