Handedness Chirality in Nature

Nature makes ample use of chirality. Let me mention a few such usages. 

Handedness is the basis of molecular recognition during protein synthesis. As the amino acid molecules are stitched, by the cell s machinery (see more in Retouches section 7.R.6), to form a protein by excision of water molecules, adjacent pairs of amino acids experience mutual interactions that are similar to the handshake. Thus, a 

FIGURE 7.9 The impact of chirality in (a) the biologically active adrenaline (epinephrine), (b) The two enantiomers of aspartame—only one of them is sweet, and it is sold under the name Nutrasweet. The other enantiomer of aspartame is bitter. All the molecules are shown also with 3D ball-and-stick representations. The arrows point to chiral centers of interest. 

FIGURE 7.10 Thalidomide with its chiral center indicated by an arrow. The ball-and-stick representation is shown on the right. 

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