Turgor pressure is the pressure of the cell sap against the cell wall. Osmotic pressure is the hydrostatic pressure that develops in a solution due to osmosis.
Turgor pressure is directly related to the water potential of the cell sap. The higher the water potential, the greater the turgor pressure. On the other hand, osmotic pressure is determined by the concentration of solutes in the solution. The more solutes there are, the higher the osmotic pressure.
So, turgor pressure is a function of water potential, while osmotic pressure depends on solute concentration.
In this article, we will learn about turgor and osmotic pressure, what is turgor pressure in plants, and what causes it. If you’ve got a Biology exam coming up, these concepts are sure to come in handy?
Difference Between Turgor Pressure And Osmotic Pressure
One important difference between turgor pressure and osmotic pressure is that turgor pressure is always positive, while osmotic pressure can be either positive or negative. This is because turgor pressure results from the cell sap pushing against the cell wall, while osmotic pressure results from the movement of water molecules across a semipermeable membrane.
Suppose the concentration of solutes on one side of a semipermeable membrane is higher than on the other. In that case, water will flow from the side with lower solute concentration to the side with higher solute concentration. This will result in a net movement of water molecules from the solution into the cell, and the resulting osmotic pressure will be negative.
Conversely, suppose the concentration of solutes on one side of the membrane is lower than on the other. In that case, water will flow from the side with higher solute concentration to the side with lower solute concentration. This will result in a net movement of water molecules from the cell into the solution, and the resulting osmotic pressure will be positive.
So, turgor pressure is always positive because it results from the cell sap pushing against the cell wall. Osmotic pressure can be either positive or negative because it depends on the direction of water flow across a semipermeable membrane.
What Is Turgor Pressure In Plants?
Turgor pressure is the hydrostatic pressure in cells that surpasses ambient atmospheric pressure. Species like plants have walled cells, which contain turgor pressure. However, other organismal kingdoms, such as animals, experience turgor pressure to a lesser extent.
Turgor pressure is important for plant cells because it helps keep them pompous or full of water. When turgor pressure is high, the cell is said to be turgid. Turgidity is necessary for the cell to maintain its shape and function properly. Osmotic pressure, on the other hand, is important for animal cells because it helps to regulate the movement of water into and out of the cell.
What Causes Turgor Pressure?
Turgor pressure is caused by osmotic water flow and occurs in plants, fungi, and bacteria. This phenomenon has also been observed in prokaryotes with cell walls. This mechanism is not seen in animal cells because the absence of a cell wall would result in the cell bursting under excessive pressure.
In summary, turgor pressure is the pressure of the cell sap against the cell wall, while osmotic pressure is the hydrostatic pressure that develops in a solution due to osmosis.
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Frequently Asked Questions?
1- In which condition the turgor pressure of the cell becomes equal to the osmotic pressure?
When a cell is placed in a solution with a concentration that is the same as its internal concentration, the turgor pressure and osmotic pressure of the cell become equal. This is because there is no net movement of water across the cell membrane, so the hydrostatic pressure inside the cell and the osmotic pressure of the solution are balanced.
2- What is the difference between turgidity and flaccidity?
When it comes to plant cells, turgidity and flaccidity refer to the state of the cell wall. Turgidity is when the cell wall is fully swollen and firm, due to the high water pressure inside the cell. Flaccidity, on the other hand, is when the cell wall is limp and floppy, due to low water pressure inside the cell. So what causes these different states? Turgidity is caused by high turgor pressure, which is created by osmosis. When a plant cell takes in more water than it loses, the water pressure inside the cell increases, causing the cell wall to swell and become firm. Flaccidity, on the other hand, is caused by low turgor pressure, which happens when a plant cell loses more water than it takes in.
3- What is the difference between root pressure and osmotic pressure?
Root pressure and osmotic pressure are two terms that are often used interchangeably, but there is a subtle difference between the two. Root pressure is the force exerted by the plant’s roots on the surrounding soil, while osmotic pressure is the force exerted by a solution on a membrane. Root pressure is caused by the plant’s roots growing in response to the pull of gravity. The roots take up water from the soil, which causes the cells in the root tips to swell. This swelling puts pressure on the surrounding soil, which the plant uses to support itself. Osmotic pressure, on the other hand, is caused by a difference in concentrations of solutes on either side of a membrane.