Transport Mechanisms in Cellular Communication

Transport is a very important process for cell cytoplasm to communicate with the external environment. Transport is any process in which the movement of matter or energy occurs from one part of a system to another. The plasma membrane, also known as cell membrane is selectively permeable. It permits some particles to pass through, while also not letting other particles to pass through. If a substance can cross the membrane then the membrane is permeable to that substance, but if a substance is not able to pass the membrane then it is impermeable to it. Transportation across the membrane occurs by one of the two means, which are active transport and passive transport. Active transport requires the cell to utilize cellular energy in the form of ATP, so it can employ protein pumps or engage in the activity of endo / exocytosis. Passive transport occurs with no energy

In most case osmosis is the diffusion of water. Osmosis is a physical process in which a solvent moves, without input of energy, across a semi permeable membrane separating two solution of different concentrations. The osmotic pressure is defined to be the pressure required to maintain equilibrium, with no net movement of solvent. Osmotic pressure depends on the molar concentration of the solute and not on it identity. It is the exact amount of pressure required to stop osmosis. The tonicity of a solution refers to the effect on cell volume of the concentration of non-penetrating solutes in the solution surrounding the cell

Active transport is the mediated transport of biochemical, and other atomic molecular substances across membrane. This process requires the expenditure of cellular energy to move molecules uphill against a gradient. It is also involves the use of a protein carrier to transfer a specifics substance across the membrane, but against its concentration