Investigate what effect different levels of concentration of sucrose solution have on the movement of water via osmosis in potatoes. EQUIPMENT Sucrose solution (0.2M, 0.4M, 0.6M, 0.8M, 1.0M) Distilled water (0.0M) Potatoes Cork borer Boiling tubes Boiling tube rack Stop clock Balance (0.0 decimal places) Tweezers Measuring cylinder Ruler METHOD Cut 6 pieces of potato with a cork borer and cut them to the same length of approximately 5 cm (measure with a ruler) Measure out 25cm³ of water and each of the sucrose solutions, using the measuring cylinder. The measurements for the solutions have to be perfect as to not change the outcome of the experiment. Pour into boiling tubes, giving the various concentrations. Label boiling tubes with concentration of sucrose solution Take measurements of each potato tube (mass) on the balance and record in a suitable table.
This researcher called his experiment" Bound water" "The water of Potato Tissue Potential". (Clemson University by Robert J. Kosinski) Quote: He talked about how, when using organic materials and beakers, there can be predictions made of how sucrose or NaCl molecules will bind up any hydrophilic solute if it is diffusing within a membranous condition. Because the potato is semi permeable , the potato tissue will always take up the water because the water is hypertonic and because it just simply moves into a concentration gradient. (Baumgarten and Feher, 1998; Weiss, 1996, pp. 216-222).
Osmosis Lab Design: a) Will the mass of a potato grow larger during Osmosis (24 hours), when in water or in a 20% solution? b) Osmosis is the movement of water molecules across a semi permeable membrane from a region of lower solute concentration to a region of higher solute concentration. Osmosis requires no energy therefore it is passive. A hypertonic solution is when there is a higher concentration of solutes on the outside of the cell. A hypotonic solution is when the substance has lower solutes than its surroundings.
Osmolarity involves the movement of water across a cell membrane which is osmosis, this movement of water can be hypertonic; a higher concentration of a solute inside the cell which means the cell loses mass, hypotonic; a lower solute concentration inside the cell than outside which means the cell gains mass, or isotonic; a solute concentration the same as the outside of the cell which means there is no net movement of water. In a hypertonic solution in a cell water will leave the cell in order to balance the solute concentration making the cell shrink, in a hypotonic solution however water will enter the cell to balance the concentration. In an isotonic solution water will not move since both sides are equal in concentration. b. Purpose-The purpose of this lab was to determine the osmolarity of plant cells by using potato cores as the cells and sugar as the solute. c. Hypothesis-My hypothesis was that if the amount of solute increases then the then potato core’s weight decreases.
OSMOSIS IN POTATO CELLS INVESTIGATION Introduction Osmosis is the passage of water from a region of higher water potential to a region of lower water potential through a partially permeable membrane. Osmosis only involves the movement of water molecules. The diagram depicts water molecules diffusing from the left hand side which has the higher water potential, to the right hand side which has the lower water potential. Only the water molecules can pass across the partially permeable membrane Figure 1 Aim The aim of this investigation is to record the effect of varying dilutions of sodium chloride solution on sections of potatoes and ascertaining the amount of osmotic activity between the two. The independent variable is varying the range of concentrations by diluting the 1M solution of sodium chloride.
This is a diffusion where the movement of water from an area of high water concentration is moved to an area of low concentration. This experiment takes place to measure the diffusion of small molecules throughout dialysis tubing. This tubing acts as a selectively permeable membrane, allowing the larger molecules to pass through, but slowly. When the two solutions on either sides of the membrane are equal and no net movement is detected, the solutions are isotonic. This means that the solutions have the same concentration of solutes.
2. Define osmosis. Diffusion of fluid through a semipermeable membrane from a solution with a low solute concentration to a solution with a higher solute concentration until there is an equal concentration of fluid on both sides of the membrane. 3. What is the main difference between osmosis and diffusion.
It is important for an IV solution to have salts in it so the water and solute can be equal to create an isotonic environment. If there wasn’t, there would either be a hypotonic causing the cell to burst, or there would be hypertonic causing the cell to shrink. We created models of living cells by using dialysis tubing. The dialysis tube represented the cell membrane to act as selectively permeable to water and some solutes. We observed different solutes (NaCl, Ovalbumin, Glucose, Sucrose, and Water) in the dialysis tubing.
The final weighing of the potato cores weighed less than initially since the water is leaving the potato in order to evenly distribute itself amongst the sucrose. Introduction: In this lab, the concept of diffusion by osmosis was explored in relation to varying concentration levels of sucrose in H2O. The Diffusion rate of glucose out of potato cells was tested in 5 different stages with the concentration of sucrose increasing each time (e.g. 0%, 25%, 50%, 75% and 100%) until 100% sucrose is reached. In cells, diffusion accounts for how substances are passed through the cell membrane (Kaisa, 2008).
Prediction: The potato chips will decrease in mass. Reasoning: Since the potato chips have a lower concentration of sugar, the water molecules from the potato chips will diffuse into the solution until they are both at the same concentration. Summary of Hypothesis The potato chips will increase in mass in solutions of lower sugar concentrations but will decrease in mass in solutions of higher sugar concentration. The Experiment -------------- I am going to carry out an experiment to measure the change in mass of potato chips left in a sugar solution for a period of 1 hour. I will carry out this experiment several times to ensure accurate results.