Factors Affecting Osmosis
The aim of this experiment is to investigate the factors affecting
osmosis. I have chosen to investigate the effect varying concentration
of sucrose solution has on the amount of osmotic activity between the
sucrose solution and a plant cell. The plant cell I have chosen to use
is a potato tuber from which I plan to cut potato chips of equal
length which I will place in test tubes filled with varying
concentrations at equal volumes of sucrose solution. After a set
amount of time I will remove the potato chips and record the change in
length.
BACKGORUND KNOWLEDGE
High water potential is a solution which has a high concentration of
water and a low concentration of solute (e.g. sugar, sucrose or salt)
or no solute at all. Therefore it can either be a very dilute solution
of something like sucrose or pure water, however in each case there is
a lot of water. Whereas low water potential is the opposite of high
water potential being a solution of low concentration of water and
high concentration of solute (sugar, sucrose or salt). Hence it can be
a concentrated solution of something like sucrose, however in this
case there is much less water.
When to solutions one of high water potential and one of low water
potential are divided by a semi-permeable membrane water molecules
will move from the solution of high water potential through the
partially permeable membrane to the solution of low water potential.
This will continue until both sides have reached a state of
equilibrium or isotonic point, which is when both solutions wither
side of the partially permeable membrane have equal water potential
neither having higher or lower potential, they are said to be
isotonic. When this occurs there is no net movement of water across
the membrane only random diffusion of particles.
What I have discussed in the previous paragraph is the process of
osmosis, however in short osmosis is defined as the net movement of
water molecules from a high water potential through a partially
Considering the fact that Marc has both been sweating and drinking minimal amounts of water, Marc is now dehydrated. This means he has less than the required amount of water for his body to complete the processes necessary to maintain its health. As stated in the question, the process of sweating causes the loss of more water than solutes. This means that as the level of water decreases, the level of solute concentration will increase, creating a change in the water to solute ratio.
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.
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.
There will be a net movement in these types of solution. The molecules will move from the hypotonic solution into the hypertonic solution. The third way a substance can cross the cell membrane is through facilitated diffusion.
* We would have to leave one end open to fill it up with the different
The purpose of this experiment is to investigate the effect of changing the concentration of sodium chloride solution on the rate of osmosis in tubes of potatoes. This was maintained using equal measurements of the potato tubes and applying them into the different concentrations of sodium chloride, 0%, 2%, 5%, 10%, 20% and 26%, in beakers then measuring the change in mass of the potato tubes afterwards. The time taken for all potato tubes to be placed in solution was 15 minutes. Can the concentration gradient of the sodium chloride solution influence on the rate of osmotic diffusion undergone by the potato tubes?
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.
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.
Osmosis is the facilitated diffusion of water across the cell membrane of a cell. The inside layer of the cell membrane is hydrophilic, meaning water cannot easily pass through the membrane. The cell membrane has to have aquaporins, which are water channel proteins, that move the water across the membrane. If there is a water and salt solution outside the cell, the salt can enter the cell by diffusion, but the cell membrane is not permeable to the water. Because there is more solute solution inside the cell, there is less water. The aquaporins move the water across the membrane until equilibrium is reached.
According to osmosis theory as the concentration of the sucrose solution increases the particles water potential increases and becomes higher than the particles that are in the
- The nurse’s mistake will increase the saltiness due to the double amount of saline in the bag.
This is because the water molecules pass from a low concentration to a high concentration, (in the potato chip). Therefore, the chips in low concentrations will gain mass and have a greater length height than in higher concentrations such as 1molar of sugar solution. If there is no gain or loss in height or mass then these will be the isotonic points of the potato cells. The isotonic point is where the cells are not increasing or decreasing in size and is known to be in a state of equilibrium. Apparatus: 1.
when to do it etc. This should lead me to good results at the end of
== = This experiment is based on the concept of Osmosis. Osmosis is the diffusion of water molecules from a region of high water concentration to a low water concentration through a semi permeable membrane (in this case, the cell potato cell membrane). The cell walls of the potato cells are semi permeable meaning that water molecules (which are small) can fit through but other bigger molecules such as glucose cannot pass through. The water molecules can flow both ways through the membrane, letting molecules both in and out.
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.