Biology Ease Staff asked 2 years ago
The specific rotation of a protein is the measure of its rotational movement around the C=O-O bond. The higher the specific rotation, the greater the tendency for the protein to rotate around this bond.
The specific rotation of a protein can be measured by using a spectrophotometer. The absorbance spectrum of each protein is measured at different temperatures and analyzed for its characteristic absorbance peak. The amount of light absorbed by each peak provides information about its molecular weight and structure.
The most common method used to determine the specific rotation of proteins is differential scanning calorimetry (DSC). DSC measures the heat released from a sample as it undergoes thermal treatment or cooling. In DSC, a sample is placed in a sealed tube containing a liquid medium at constant temperature and pressure. At regular intervals throughout the experiment, samples are taken out of the tube and heated or cooled in an oven until they reach equilibrium with their surroundings; these samples are then placed back in their original position in order to continue measuring heat release. As long as there is no significant change in enthalpy or entropy during this process, any changes in enthalpy and entropy would be caused by thermal reactions taking place in the sample. DSC is used to measure the heat of fusion, heat capacity, thermal conductivity, and glass transition temperature of a variety of materials.