Osmosis and tonicity Video transcript - In the first video where we introduced the idea of diffusion and concentration gradients, we had a container with only one type of particle in it, we had these purple particles. And in our starting scenario we had a higher concentration of the purple particles on the left-hand side than we had on the right-hand side.
By Chris Deziel; Updated April 26, Osmosis is a process that occurs between two containers separated by a semi-permeable barrier. If the barrier has pores large enough to allow water molecules to pass but small enough to block the molecules of a solute, water will flow from the side with the smaller concentration of solute to the side with the larger concentration.
This process continues until either the concentration of solute is equal on both sides or the pressure resisting volume change on the side with the greater concentration exceeds the force driving the water through the barrier.
This pressure Osmosis concentration gradient osmotic or hydrostatic pressure, and it varies directly with the difference in solute concentration between the two sides. In a solution with more than one solute, sum the concentrations of all the solutes to determine the total solute concentration.
Osmotic pressure depends only on the number of solute particles, not on their composition. Osmotic Hydrostatic Pressure The actual microscopic process that drives osmosis is a bit mysterious, but scientists describe it this way: Water molecules are is a state of constant motion, and they migrate freely throughout an unrestricted container to equalize their concentration.
If you insert a barrier into the container through which they can pass, they will do so. However, if one side of the barrier contains a solution with particles too large to get through the barrier, the water molecules passing through from the other side have to share space with them.
The volume on the side with the solute increases until the number of water molecules on both sides is equal. Increasing the concentration of solute reduces the space available for water molecules, which reduces their numbers.
This in turn increases the tendency of the water to flow into that side from the other side. To anthropomorphize slightly, the greater the difference in concentration of water molecules, the more they "want" to move across the barrier to the side containing the solute.
Put a lid on a rigid container to prevent the volume from changing and measure the pressure needed to keep the water from rising while you measure the concentration of the solution on the side with the most solute.
Relating Osmotic Pressure to Solute Concentration In most real situations, such as roots drawing moisture from the ground or cells exchanging fluids with their surroundings, a certain concentration of solutes exists on both sides of a semi-permeable barrier, such as a root or cell wall.
Osmosis occurs as long as the concentrations are different, and the osmotic pressure is directly proportional to the concentration difference. It only depends on how many of them there are.
Thus, if more than one solute is present in a solution, the osmotic pressure is: Cn where C1 is the concentration of solute one, and so on. Mix a tablespoon of salt in a glass of water and put in a carrot. Water will flow out of the carrot into the salty water by osmosis, and the carrot will shrivel.
Now increase the salt concentration to two or three tablespoons and record how much more quickly and completely the carrot shrivels.
The water in a carrot contains salt and other solutes, so the reverse will happen if you immerse it in distilled water: The carrot will swell.So, the concentration gradient was at its maximum, for this reason the highest rate of osmosis took place at this concentration.
Still, as the sucrose concentration altered to lesser values the loss in mass from the potato also decreased.
Osmosis is the movement of a solvent across a semipermeable membrane toward a higher concentration of solute (lower concentration of solvent).
In biological systems, the solvent is typically water, but osmosis can occur in other liquids, supercritical liquids, and even gases.
Also, steeper gradient increased rate of osmosis demonstrated by the fact that Bag D increased faster than Bag C (fig. 1), supporting the second hypothesis that higher concentration gradient will result in higher diffusion rate (osmosis).
The Effect of Solute Concentration on the Rate of Osmosis Aim: To test and observe how the concentration gradient between a potato and water & sugar solution will affect the rate of osmosis.
Osmosis and tonicity. Hypertonic, isotonic, and hypotonic solutions and their effect on cells. Concentration gradients.
Osmosis. Hypotonic, isotonic, and hypertonic solutions (tonicity) osmosis is the net movement of water across a semipermeable membrane from an area of lower solute concentration to an area of higher solute.
Concentration gradient - The movement of osmosis is affected by the concentration gradient; the lower the concentration of the solute within a solvent, the faster osmosis will occur in that solvent. Light and dark – They are also factors of osmosis; since the brighter the light, the faster osmosis takes place.