Changes

</blockquote>

</blockquote>

Now we do know.  X-ray crystallographic studies in 1951 confirmed that the levorotatory and dextrorotatory forms of tartaric acid are mirror images of each other at the molecular level and established the absolute configuration of each.  The same approach has been used to demonstrate that although the amino acid alanine has two stereoisomeric forms alanine in proteins exists exclusively in on form, the L isomer.

Now we do know.  X-ray crystallographic studies in 1951 confirmed that the levorotatory and dextrorotatory forms of tartaric acid are mirror images of each other at the molecular level and established the absolute configuration of each.  The same approach has been used to demonstrate that although the amino acid alanine has two stereoisomeric forms alanine in proteins exists exclusively in on form, the L-isomer (levorotatory).

==References==

==References==