Diffusion and Osmosis

The life of the cell is dependent on the materials that it receives and manipulates to attain resources to maintain the processes important to life, i.e. to remain in homeostasis to the best of its ability. The membrane was an important development to the cell and it allows for the separation of chemical processes that are inside the cell and those that are outside the cell. This management of material is dependent on the external environment and the flow of materials in and out (diffusion) can be attributed to heat flows (thermodynamics) and molecular shape resulting from electronic configuration.

The net movement of molecules from one side of the semipermeable plasma membrane to the other side is completed with the support of integral proteins that stretch from one side of the phospholipid bilayer to the other. At the point where molecules contact the integral protein (at the active site), the integral protein changes shape to assist in the active transport (energy-using) process of moving the material into or out of the cell. Sometimes the permeable membrane is not large enough to accept the materials and the cell has to make some sort of large enough opening for the material to pass through causing massive reorganization processes among the phospholipid components of the membrane.

In order to understand the concept of diffusion through the membrane you can do experiments in recording the differences One of these experiments is the diffusion of molecules in and out of dialysis bags. Another one of these examples is using real potato cells and real onion epithelial skin cell samples. Analysis of the collected data and observations can provide for improved understanding of cell permeability, active transport, etc.

The set of dialysis bags are used to illustrate the semipermeable nature of cells. The data that is collected as a result can then be compared to data collected in testing chunks of potato tissue and their absorption (or lack thereof) of the surrounding solute solution. Use concentrated solutions within the dialysis bags to test the diffusion of concentrated substances across the simulated membrane.

The first set of procedures involved the addition of solute concentration to the external environment (metaphorically “the extracellular matrix” even though it did not simulate entirely the same environment as the real extracellular matrix). Then, the experiment determined whether or not diffusion occurred. See the analysis.