AP BIOLOGY

Detailed explanation-1: -An optically active compounds exists in two isomeric forms that rotate the plane polarized light in opposite directions. They are called optical isomers and the phenomena is called optical isomerism. Mixture. Optical isomers have the same physical properties: Melting point, boiling point, density etc.

Detailed explanation-2: -All molecules, whether chiral or achiral, are able to rotate plane-polarised light due to interaction with the electron cloud of the molecule. For a particular molecule, the extent and direction of rotation depends on the orientation of the molecule in relation to the plane-polarised light.

Detailed explanation-3: -Optical isomers are named like this because of their effect on plane polarized light. Simple substances which show optical isomerism exist as two isomers known as enantiomers. A solution of one enantiomer rotates the plane of polarisation in a clockwise direction. This enantiomer is known as the (+) form.

Detailed explanation-4: -Optically active compounds exist in pairs of isomers. One that rotates the plain of PPL to right (clockwise) is called dextro rotatory, while the one that rotates it to left (anti clockwise) is called laevo rotatory isomer.

Detailed explanation-5: -Enantiomers have identical physical properties*, with one exception: enantiomers rotate plane-polarized light in equal and opposite directions, which is why they are sometimes called “optical isomers”.