Final answer:
Researchers used techniques like Freeze Fracture Electron Microscopy, EM Cytochemical demonstrations, and biochemical assays with electrophoretic separation to study the plasma membrane's overlap between domains and its asymmetry.
Step-by-step explanation:
Researchers have utilized various techniques to determine the degree of overlap between different plasma membrane domains. In the study of membrane structure and function, methods like Freeze.
Fracture Electron Microscopy and Electron Microscopy Cytochemical demonstrations have been instrumental in confirming the asymmetry of plasma membranes and their structural components.
For instance, cytochemical methods confirm that only the external surfaces of plasma membranes are sugar-coated, which points to the presence of a glycocalyx.
To further understand membrane protein distribution, biochemical experiments involving proteolytic enzymes and subsequent protein extraction have been carried out.
Electrophoretic separation of these proteins has revealed differences in the component makeup, demonstrating the asymmetry of the plasma membrane.
Moreover, the experimentation involving focal adhesion proteins and their interaction and stability with cytoplasm suggests the involvement of non-equilibrium effects stabilizing the plasma membrane domains.
The overarching model that ties together the structure and function of the plasma membrane is referred to as the fluid mosaic model, which was proposed by Singer and Nicolson.
According to this model, the plasma membrane's dynamic nature comes from a varied mixture of phospholipids, cholesterol, proteins, and carbohydrates, which allows the membrane to maintain a certain fluidity while structurally resembling a sandwich.
This model has evolved but continues to be the most acceptable explanation for plasma membrane structure.