Abstract
Lateral diffusion measurements, using the photobleaching techniques, have provided unique and quantitative data on the random translational motions of proteins and lipids of membranes. Proper interpretation of this body of data can yield new insight into the structure of biomembranes. A comparative review of the lateral diffusion of membrane components in artificial lipid bilayers and of the same components in natural membranes is presented to demonstrate the effects of protein concentration and peripheral constraints on lateral mobility. Recent data on the effects of cell‐substrate and cell‐cell contact on lateral diffusion are reviewed. Finally, some experimental perspectives are offered in terms of emerging biophysical and biological technology.