<0 3B: ß-strand region20 30 40 50 60Temperature (t), °CFig. 3. Infrared absorbance in the a-helix region at 1657cm“1(A) and the extended chain (ß-strand) region at1626 cm' 1as a function of temperature in photosystemII particles incubated between 25 and 55 °C.at 1657 cm...