What is a concentration gradient?

Concentration of substance is the number of molecules present in a given volume of liquid or gas. The concentration gradient occurs between the area of ​​high concentration and the low concentration area. In nature, this usually occurs on each side of the border of cells or membranes. If the particles can freely exceed the membrane, a process called diffusion takes place, where particles move through a concentration gradient with a clean flow towards the low concentration area. This movement of molecules on the gradient eventually leads to both areas to become the same in concentration, a condition known as a dynamic balance. The process known as diffusion means that molecules tend to move away from areas where there are high concentrations and move towards less concentrated areas. Another type of moleculas also tends to mix together. Both of these processes work when the smell gradually spreads around the room and mixes with air molecules. Finally, the concentration gradient removes even distribution of particles.

In the process known as osmosis, the molecules seem to move in the opposite way through gradients, from low to high concentrations. This can be seen in cases where the cell membrane blocks the browsing particles because they are too large. Molecules of water in solution can be small enough to pass through the membrane, even if the dissolved particles are not.

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water molecules move from an area outside the cell, where particle concentration is relatively low, inside the cell, where there is a high concentration of particles. Like diffusion, this movement reduces the concentration gradient between the two areas. It can be denapsed as a special form of diffusion, as water molecules actually move from the area of ​​high water concentration into the low water concentration area.

Sometimes cell biology works actively to move particles against concentration gradient and against the influence of osmosis and diffusion. The game appears what is called active transport mechanismNisms such as a sodium potasia pump. This pump transports sodium and potassium molecules over the cell membrane, ensuring that a high concentration of potassium and high sodium concentration inside the cell. The process requires ATP, a special molecule in which the energy is located inside the cell.