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.
Introduction:
Osmosis is defined as, diffusion, or net movement, of free water
molecules from high to low concentration through a semi-permeable
membrane.
When a substance, such as sugar (which we will be using in the
experiment we are about to analyse), dissolves in water, it attracts
free water molecules to itself, and in doing so, stops them from
moving freely.
The effect of this, is that the concentration of (free) water
molecules in that environment goes down. There are less free water
molecules, and therefore less water molecules to pass across a
semi-permeable membrane, through which sugar molecules and other
molecules attached to them are too big to diffuse across with ease.
In the diagram below on the right, we see two solutions divided by a
partially/selectively permeable membrane (i.e. one that is porous, but
allows water molecules through faster than dissolved substances).
Text Box: Originally, the two solutions were; pure water, on the left,
and sugar solution with a high sugar concentration, on the right. The
pure water solution is said to have higher water potential than the
concentrated sugar solution, because the water will flow from the area
of high concentration of free water molecules (the dilute solution),
to the area of low concentration of free water molecules (the
concentrated solution). In other words, to the sugar solution.
However, in this diagram we see that osmosis has been taking place for
a short while, because water molecules have started to diffuse to the
right, across the membrane, so that there are now many present on the
right side of the membrane, and a few sugar molecules are starting to
diffuse across the membrane in the opposite direction, to the left
side of the membrane as we see it.
Through moving from an area of lots of free water molecules, to an
When the cell has all the water it can take inside of it the osmosis
Osmosis Experiment Planning Aim: The main subject that I will be planning to investigate is the effects of a concentrated sucrose solution on potato cells on the basis of the Osmosis theory. Background knowledge: The plant cell and its structure To understand osmosis in detail I will need to explain the plant cell (which is the cell included in the osmosis experiment) and its cell membrane. Below I have a diagram of a plant cell: [IMAGE] Osmosis is about the movement of particles from a higher concentrated solution to a lower concentrated solution to create an ethical balance via a partially or semi permeable cell membrane. Osmosis in simple terms is the exchange of particles between the cytoplasm inside the cell and the solution outside the cell. What makes this exhange is the partially permable cell membrane.
If the concentration of one side of the membrane is greater than the molecules will travel from the higher to lower concentration. Eventually there will be a dynamic equilibrium and there will be no net movement of molecules from one side to the other. Osmosis is the diffusion of water. Like diffusion, the water moves from a region of higher water potential to a region of lower water potential.
* We would have to leave one end open to fill it up with the different
The direction of osmosis depends on the relative concentration of the solutes on the two sides. In osmosis, water can travel in three different ways. If the molecules outside the cell are lower than the concentration in the cytosol, the solution is said to be hypotonic to the cytosol, in this process, water diffuses into the cell until equilibrium is established. If the molecules outside the cell are higher than the concentration in the cytosol, the solution is said to be hypertonic to the cytosol, in this process, water diffuses out of the cell until equilibrium exists. If the molecules outside and inside the cell are equal, the solution is said to be isotonic to the cytosol, in this process, water diffuses into and out of the cell at equal rates, causing no net movement of water. In osmosis the cell is selectively permeable, meaning that it only allows certain substances to be transferred into and out of the cell. In osmosis, the proteins only on the surface are called peripheral proteins, which form carbohydrate chains whose purpose is used like antennae for communication. Embedded in the peripheral proteins are integral
molecules go in and out of the cell. There is no net movement of water
Investigate the Osmosis of Potato Cells in Various Salt Solutions. Introduction I have been asked to investigate the effect of changing the concentration of a solution on the movement of water into and out of potato cells. I will be able to change the input of my experiment. The input variable is the concentration of the solution.
If the concentration of sucrose increases, then the mass of the potato will decrease. However, if the concentration of the solution in the beaker is less than that of the potato (such as distilled water), then the mass of the potato will increase. So, as the concentration of sucrose increases the rate of osmosis increases.
The Functions of Osmosis Osmosis is the passive transport of water through a selectively permeable membrane, a membrane that allows certain needed particles to pass through it more easily than others. Pores in this type of membrane are large enough for water to pass effortlessly through it. The flow of water during osmosis depends on the concentration of a solute either within a cell membrane or surrounding the membrane. Water naturally flows from a hypertonic solution, an area of high concentration of solute, to a hypotonic district, a solution containing a lower concentration of solute.
Osmosis in Carrots Background Osmosis is the diffusion of water from a dilute solution to a more concentrated solution through a partially permeable membrane, which allows the pass of water molecules but not solute molecules. [IMAGE][IMAGE][IMAGE][IMAGE][IMAGE][IMAGE][IMAGE][IMAGE]If a cell is placed in a less concentrated solution water enters because the less concentrated solution will have a high concentration of water than the inside of the cell. Once the cell takes in maximum water the cell becomes turgid. If the cell was to be placed in a high concentrated solution, water would leave the cell because the cell would contain a low concentrated solution. So in the low concentrated solution there will be a high concentration of water and in the high concentrated solution there will be a low concentration of water.
- The nurse’s mistake will increase the saltiness due to the double amount of saline in the bag.
Most cell membranes are like that, being permeable to water and some solutes only. Osmosis is therefore the diffusion of water through a partially permeable membrane. The basic principles of diffusion apply here.
when to do it etc. This should lead me to good results at the end of
Osmosis in Potato Tubes Osmosis: Osmosis is the movement of water molecules through a semi-permeable membrane from a high concentration to a low concentration. Diagram: [IMAGE] [IMAGE] Aim: To see the effects of different concentration of sugar solution on Osmosis in potato tubes. Key factor: In the investigation we change the sugar solution from: 0%-10%-20%-30%-40%-50% this is the independent variable; the dependant variable is the change in mass. Prediction: I predict that all the potato tubes in pure water or low concentration sugar solution will swell because water enters their cells by osmosis.
Osmosis is the passage of water molecules from a weaker solution to a stronger solution through a partially permeable membrane. A partially permeable membrane only allows small molecules to pass through, so the larger molecules remain in the solution they originated in. Solute molecule [IMAGE] [IMAGE] Water molecule [IMAGE] The water molecules move into the more concentrated solution. When water enters a plant cell it swells up. The water pushes against the cell wall and the cell eventually contains all that it can hold.