Potato Osmosis Assignment Example | Topics and Well Written Essays - 2500 words

Potato Osmosis - Assignment Example The researcher states that even the simplest unicellular protozoan needs to communicate with the external environment for survival because it needs to ingest food, eliminate waste products and toxins of metabolism and exchange gases through respiratory mechanisms. This communication is further developed in a more intricate manner in the multicellular organisms where exchanges take place within and between the cells in carrying out their assigned physiological functions. All cells are bound on the outside by a limiting membrane akin to a boundary wall which separates and protects the cellular components from the external environment. This membrane is known as the cell wall and the plasma membrane in plants and animals respectively. This membrane is a specialized component which selectively permits passage of water and other components across it either inward or outward depending upon the gradient of the fluid environment and internal contents or due to selectivity for particular molec ules through specialized pores or channels. Two of the processes by which such exchanges take place are known as diffusion and osmosis. Diffusion is simply the movement of molecules from a region of higher concentration to a lower concentration (intranet.landmark.edu). Diffusion occurs within a single compartment or environment where molecules move from a region of higher concentration to a lower concentration until equilibrium is reached. Such diffusive activity can take place inside a single cell. Osmosis too is also a movement of components within a solution either from a higher gradient to a lower one or selectively under active transport systems controlled by cellular physiology, but this diffusion occurs across a semi-permeable membrane such as the plant cell wall or the animal plasma membrane. The plant or the animal cell walls are selectively permeable for certain molecules and do not allow other molecules to pass through them.