Handedness Chirality and Isomerism

FIGURE 7.6 (a) Tamoxifen, (b) 4-Hydroxytamoxifen inside the estrogen receptor (structure was drawn using 3ERT.pdb). 

Pasteur discovered handed isomers in the nineteenth century when he passed polarized light through a solution of chiral molecules. Polarized light is a form of light that is seen only in a certain plane, while all other directions are dark. When such a light hits a chiral molecule, the molecule rotates the plane of polarization and the outcoming light is polarized in a rotated plane. Enantiomers rotate the plane of 

FIGURE 7.8 Amino acids are chiral and snuggle nicely with their respective left and right hands. Proteins are made only from left-handed amino acids. This image was created by NASA. It is in the public domain, and it was obtained from http //en.wikipedia.org/wiki/ File Chirality with hands.svg. 

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