Editing Circular polarization (section)

==Dichroism==
{{Main article|Circular dichroism}}
'''Circular dichroism''' ('''CD''') is the differential absorption of left- and right-handed circularly polarized [[light]]. Circular dichroism is the basis of a form of [[spectroscopy]] that can be used to determine the [[Chirality (chemistry)|optical isomerism]] and secondary structure of [[molecule]]s.

In general, this phenomenon will be exhibited in absorption bands of any [[optical activity|optically active]] molecule. As a consequence, circular dichroism is exhibited by most biological molecules, because of the [[Dextrorotation and levorotation|dextrorotary]] (e.g., some [[sugar]]s) and [[Dextrorotation and levorotation|levorotary]] (e.g., some [[amino acid]]s) molecules they contain. Noteworthy as well is that a [[secondary structure]] will also impart a distinct CD to its respective molecules. Therefore, the [[alpha helix]], [[beta sheet]] and [[random coil]] regions of proteins and the [[Nucleic acid double helix|double helix]] of [[nucleic acid]]s have CD spectral signatures representative of their structures.

Also, under the right conditions, even non-chiral molecules will exhibit [[magnetic circular dichroism]] — that is, circular dichroism induced by a magnetic field.