| Book Edition | 8th Edition |
| Author(s) | Brown |
| ISBN | 9781305580350 |
| Publisher | Cengage Learning |
| Subject | Chemistry |
Of the 20 protein-derived amino acids shown in Table 27.1, which contain
(a) no chiral center and
Of the 20 protein-derived amino acids shown in Table 27.1, which contain
(b) two chiral centers?
A molecule is chiral if at any center, four different groups are present and has a non-superimposable mirror image. The word non-superimposable means placing one molecule on the top of the other molecule will not give the same molecule.
Achiral molecules are those whose mirror images are superimposable and also they do not contains chiral center. In amino acids, the glycine is the only amino acid which does not contain any chiral center as it do no have four different groups (2 hydrogens present on the carbon center) and thus, glycine is an achiral molecule. The structure of the glycine is shown below.
Glycine (Gly, G).
Here, Chiral centers are carbon atoms that are attached to 4 different groups of atoms. The asterisk represents the chiral center. Molecules having non-superposable mirror image are known as Chiral molecules. Molecules having superimposable mirror images are known as Achiral molecules.
Isoleucine (Ile, I), Threonine (Thr, T)
