Infrared Spectra of Nitella Cell Walls and Orientation of Carboxylate Ions in the Walls

Infrared spectra of film specimens of the cell wall of Nitella were recorded in the untreated state, after acid treatment, and after treatment for removal of pectic substances and hemicellulose. Assignment of the bands in the spectrum of the wall was made. Polarization measurements on the wall indicate that in addition to cellulose, carboxylate ions, which are attributable to pectic substances, are oriented in the wall. The nature of the bonds holding the oriented carboxylate ions is described.