Preview

Osmosis: Potato Tuber Lab

Good Essays
Open Document
Open Document
565 Words
Grammar
Grammar
Plagiarism
Plagiarism
Writing
Writing
Score
Score
Osmosis: Potato Tuber Lab
Lab Topic: Movement of Materials Across the Cell Membrane—Potato Tuber Cells

Introduction:
Osmosis is a form of diffusion in which water diffuses through a selectively permeable membrane from a region of high concentration to a region of lower concentration. This form of diffusion takes place when the molecules in high concentration are too large to move through the membrane. Three factors that determine cell membrane permeability are shape, size, and polarity. For this experiment, it must be kept in mind that sucrose is not permeable to the cell membrane, for it is too large to pass through. The cell membrane functions to protect, separate, and regulate what goes in and out of a cell. It also allows cells to control their internal chemical environment and the availability of important materials. In a hypertonic solution, there is a greater concentration of solute inside a cell compared to another solution (water will flow from out of the potato cells and the mass will decrease). In a hypotonic solution, there is a lower concentration of solute compared to another solution (water will flow into the potato cells and the mass will increase).

In this potato tuber lab experiment, the weight of each potato tuber after being sliced into thin disks and rinsed was taken and recorded. The potato disks were then individually placed in sucrose solutions for exactly an hour, each cup being swirled every ten minutes. At the end of the hour, each group of potato tuber slices was weighed a second time to determine if there was a change in mass due to the sucrose solution. The percent change in weight among the different potato tubings was determined in order to confirm or deny our hypotheses.

My null hypothesis was that the potato would not be affected by the sucrose solution, the osmotic concentration would neither increase nor decrease, therefore there would be no change in mass seen. My alternate hypothesis was that the potato would be affected by the sucrose

You May Also Find These Documents Helpful

  • Good Essays

    This overall flow of water from a dilute area of high water potential to a more concentrated solution of low water potential across a partially permeable membrane is called osmosis. I predicted that the swede cylinders which are put in a test tube with a low potential of sucrose solution would become turgid because the water molecules that are present in the swede will move away from an area of higher potential of water molecules to an area that has a lower potential of water molecules, this means that the swede sample will gain mass and become full almost to an extent where it is ready to burst. The swede samples that are going to be put in a test tube with a high potential of sucrose solution will become flaccid because the swede cylinder will have a higher potential of water molecules and so these molecules will diffuse into the sucrose solution as it has a lower water potential, this means that the potato sample will shrivel and loose mass.…

    • 1139 Words
    • 5 Pages
    Good Essays
  • Better Essays

    Biolab 1208 Lab Report

    • 840 Words
    • 4 Pages

    The purpose of this experiment is to calculate the mass/change in mass of plant tissue, in our case potato tubers. The change in mass of the potato tuber disk determines the osmotic concentration. After soaking the potato tubers in different concentrations of sucrose, then calculating the percent change in mass, we can determine the osmotic concentration. The…

    • 840 Words
    • 4 Pages
    Better Essays
  • Satisfactory Essays

    This exercise involves estimating the osmotic concentration of potato tuber cells by using a change in mass method. The null hypothesis states that there will be no change of mass of the potato disks after they have been incubated in any sucrose solution. This means that the concentration of sucrose that the potatoes are in will no effect the movement of water in or out of the potato cells. However, the alternative hypothesis states that the mass of the potato disks will increase after they have been incubated in a hypertonic solution. The mass of the potato disks will decrease after they have been incubated in a hypertonic solution. After the results have been gathered, appropriate estimations can then be made as to what the osmotic concentrations of the potato tuber cells are. Osmotic concentrations will either be hypertonic, hypotonic or isotonic depending on the results of mass change of the potato tubers.…

    • 367 Words
    • 2 Pages
    Satisfactory Essays
  • Good Essays

    AP BIO

    • 386 Words
    • 2 Pages

    To address this problem created by the lab tech, I would set up an experiment like the one we did in AP biology to identify the molarity of the unknown sucrose solutions. First I would pour an equal volume of each solution into beakers labeled A, B, C, and D. I would also have a beaker of the same amount of distilled water to serve as a control for the experiment. Then I would obtain several baby carrots, 4 per beaker. I would mass the groups of 4 potatoes before placing them in their respective beakers of solution. potatoes do have semipermeable cell membranes (water should be able to pass, but not necessarily the larger sucrose), but in order to allow materials to pass through the carrots and be able to measure a change I would let the potatoes sit overnight (or at least for several hours after placing them in the solutions). Upon returning to the lab, I would extract the carrots from their solutions, blot them dry, mass them again, and then calculate the percent change in mass of the carrots after sitting in solution. I would expect that the carrots in water as well as possibly the 0.2 M sucrose would gain mass. The potatoes in 0.4 M, 0.6M and 0.8M sucrose solution should show greater percentage mass loss with each increasing concentration of sucrose in solution.…

    • 386 Words
    • 2 Pages
    Good Essays
  • Good Essays

    Lab Report

    • 610 Words
    • 3 Pages

    3. I suspect that the mass of the potato would decrease just as it did with the sucrose…

    • 610 Words
    • 3 Pages
    Good Essays
  • Good Essays

    1) As the Concentration of the Sucrose Solution increases, the more the potato’s mass decreases. This is due to the solution being hypotonic. So, as the solute concentration gets higher, the potato’s water concentration will get…

    • 898 Words
    • 4 Pages
    Good Essays
  • Better Essays

    This experiment gave a visual understanding of osmosis and diffusion. The first experiment proved that solutes would move down a concentration gradient if permeable to the selective membrane. The second experiment proved different solute concentrations affect the movement of water, depending on the solute concentration inside the cell. The purpose of this lab was to look for different solutes that can cross an artificial membrane and to observe the effect of different concentrations of sucrose on the mass of a potato cell. Results for Part One suggested that the molecular weight of albumin and starch was too large to pass through the dialysis tube, but glucose and sodium sulfate molecules were small enough to pass through the dialysis tube. Also, a decrease in water weight occurred due the dialysis tube being placed in a hypertonic solution. Results for Par Two showed the potato cell having a molar concentration of 0.2734, which caused sucrose concentrations above 0.2 M to have a decrease in mass. Inversely, sucrose concentrations below 0.2 M caused an increase in mass.…

    • 2179 Words
    • 9 Pages
    Better Essays
  • Best Essays

    Biology Eei

    • 3499 Words
    • 14 Pages

    The aim of this experiment was to test the effect of surface area on osmosis and the effect of solute concentration on osmosis. To test this aim to hypotheses were devised. 1) If potato pieces are immersed in various salt solutions, then the pieces with the greatest surface area to volume ratio will experience the greatest weight change, because more water can move by osmosis across the potato cell’s semi permeable membrane. 2) If potato pieces are immersed in various salt solutions, then the pieces immersed in the most concentrated solution will experience he greatest weight change, because more water must pass across the potato cells semi permeable membrane by osmosis to achieve an equilibrium. The results from testing these hypotheses did not support either and were shown to be flawed because they did not reflect the theories of osmosis relating to surface area to volume ration and salt concentration.…

    • 3499 Words
    • 14 Pages
    Best Essays
  • Good Essays

    4D- The hypothesis was supported because having no net movement meant that the sucrose solution 0 M would be isotonic in the slice of potatoes. The line from the graph that crosses the x-axis represents the molar concentration of sucrose with water potential that is equal to the potato tissue water potential. In this concentration there was no net gain or loss of water from the tissues.…

    • 1371 Words
    • 6 Pages
    Good Essays
  • Satisfactory Essays

    Osmosis Lab Response

    • 310 Words
    • 2 Pages

    As the concentration of a solute in water will, through osmosis, transfer until the concentration is nearly the same both inside the cell, or in this case potato, and outside of the cell, the potato strips both gained and lost mass due to the different concentrations of sugar in water. As expected, the potato strips placed in the concentration of sugar water closest to the concentration of sugar water in a potato had the least amount of change in mass. As the potato strips placed in substance Z and substance A both changed 7%, the concentration of sugar water in a potato must be somewhere in between a concentration of 0.4 and 0.6. One source of error for this lab is that the amount of substance placed into each Dixie cup was not measured and therefore were not consistent. If this lab were repeated, it is suggested that the amount of substance be measured in order to produce more consistent results.…

    • 310 Words
    • 2 Pages
    Satisfactory Essays
  • Powerful Essays

    Potato Osmosis Lab

    • 3353 Words
    • 14 Pages

    Aim To observe and measure the effect of osmosis on the mass of potato using a starch solution. Introduction In order to measure the effect of osmosis, eighteen pieces of potato were cut and placed in six groups, each group of three pieces cut to weigh as close as possible to one another. For each potato group, a test tube was half filled with a starch solution varying in concentration from 0% (water) to 1%. Hypothesis…

    • 3353 Words
    • 14 Pages
    Powerful Essays
  • Good Essays

    vugj

    • 460 Words
    • 2 Pages

    Introduction: Osmosis is the diffusion of water from a higher concentration to a lower one through a semi-permeable membrane and occurs in the cells of organisms. It is affected by the addition of solute which would lower the water potential, making water potential and solute concentration inversely related. The concept of osmosis loosely described is that the presence of more solute outside the cell means the presence of less solvent (or water molecules in this case) and vice versa; the goal of osmosis is for the water molecules inside and outside of the cell to be equal, causing equilibrium and a stop to net water movement. The goal for a recent lab was to test whether cubes of potato would gain or lose weight depending on the amount of molar concentration of sucrose they soaked in. Solutions made of different molar concentrations of the solute sucrose were prepared before this lab. Potato cubes were weighed and recorded as the initial mass in the data. Four cubes of potato were placed into 100 mL of each solution and let stand overnight. The cubes were then taken out for the final total mass to be measured and recorded. In this experiment, the potato cubes were the dependent variables, and the molar concentrations were the independent or manipulated variables.…

    • 460 Words
    • 2 Pages
    Good Essays
  • Powerful Essays

    PotatoLabReport

    • 1275 Words
    • 6 Pages

    interior of the cell. The process by which water crosses membranes from region of high water concentration to regions of low water concentration is called Osmosis. Osmosis is the process whereby water moves across a cell membrane by diffusion. Diffusion takes place when the molecules of a substance tend to move from areas of higher concentration to areas of lower concentration. Cells must tightly control the process of osmosis otherwise they will die. Plants with too little water will wilt. This happens when water moves out of the cells by osmosis. Without this water there is little pressure inside the cell and the plant can no longer support itself against the pull of gravity.This experiment is to find out the water potential of potato cells . Water potential is the ability of water to move down gradient of water potential through partially permeable membrane until the gradient is constant.The purpose of this investigation is to see how a plant , in this case a potato , reacts to different concentrations of sucrose. Hypothesis:If we place potatoes in sucrose solutions then as the concentration goes up, the change in…

    • 1275 Words
    • 6 Pages
    Powerful Essays
  • Better Essays

    Osmosis Lab Report

    • 1250 Words
    • 5 Pages

    The purpose of this experiment was to test different solute concentrations on the rate of osmosis. Artificial cells were filled with different solute concentrations and placed in water and weighed at equal time intervals to show how the water moves across cell membranes and down its concentration gradient into the lower concentrated area. The weights of the cells were recorded each interval, and then the rate of osmosis was found by calculating the corrected cumulative change in weight. The prediction made was that the cells with the higher solute concentrations would have a higher rate of osmosis and the cell filled with water and placed in 40% sucrose solution would have the highest negative weight change.…

    • 1250 Words
    • 5 Pages
    Better Essays
  • Satisfactory Essays

    Osmosis Intro

    • 500 Words
    • 2 Pages

    Percentage change in mass of the potato is measured in each case and plotted against sucrose concentration to determine a sucrose concentration causing no change in mass. The water potential is determined from this sucrose concentration by reference to the data supplied. (see appendix A)…

    • 500 Words
    • 2 Pages
    Satisfactory Essays