Hypotonic means less salute and more water. For this lab, we can apply these principles to plant cells. The plant cells have a semi permeable membrane so they can experience osmosis and diffusion as discussed earlier. When it comes to the potato cells, added with NaCl (salt) it will experience a reaction changing the form of the cells. The hypothesis of this experiment goes as follows, If we place potato cells in a salt solution, then the cells will shrink.
This will occur because the water and glucose are small enough to diffuse out of the pores in the dialysis bag, but the starch molecules are too large to fit through 2. If a solution is very hypertonic, then the most amount of water will diffuse across the semi-permeable membrane into the dialysis tubing. This occurs because the higher concentration of solute, the more water it takes to reach equilibrium, thus, the faster rate of osmosis. 3. If we place the potato in a sucrose solution with a similar solute concentration as a potato, then the least amount of water will diffuse into or out of the potato cells.
Effect of Surface Area to Volume Ratio on Diffusion Rate of Glucose from Potatoes Abstract: The experiment was conducted to determine if differences in surface area had a significant effect on diffusion rate of glucose from potatoes. Potato samples of three different lengths were collected through a process of coring along the middle of the vegetable. Cores were soaked in distilled water for a period before an o-dianisidine-enzyme solution was added. Glucose diffusion rates were determined by using a spectrometer after a period of incubation of the potato samples. Glucose levels were measured at 0.52, 0.57, and 0.67 showing that an increase in surface area corresponded with a non-significant (p=0.096) increase in the glucose diffusion rate.
(Damon, )Since the movements of substances in passive transport take place from an area of high concentration to an area of lower concentration until both areas reach equilibrium, the water molecules will move from the potato strips to the sugar solution when there is less water concentration in the solution. Therefore, this means that as the sugar solution concentration increases, there will be more sugar molecules in the solution and less water molecules, therefore lowering the water concentration in the solution, causing the water molecules from the potato strips to move from the higher concentration area to the sugar solution with lower concentration. Vise versa, when there is lower concentration of sugar solution, there will be an increase of water concentration in the solution, therefore water molecules will move from the solution to the potato strips where there will be a relatively lower water concentration. IV) Variables: Independent- concentration of sugar solution (mol per dm³) Dependent- change in length of potato strip (cm) Control- initial length of potato strips (2cm); type of solution (sugar); type of potato b) Controlling Variables I) Independent: - The concentration of the sugar solution would be changed by using different volume of solvent to dilute the solute which would be measured by the
If the area around a cell has a higher water concentration it will gain water by osmosis. This is because the water molecules surrounding the potato cell are able to pass freely across the cell membrane in both directions; therefore more water will enter the potato than will leave it so it will swell up. Furthermore, if the area around the potato’s cells has a lower concentration of water than the cell will loose water by osmosis due to more water diffusing out through the partially permeable membrane than entering the cell, this will lead to a reduction in the size of the cell. When the concentration of water molecules in the potato is near equal to that of the area around it, the rate of osmosis will decline and the cell will stay the same size, as there is an equal amount of water entering the cell than there is leaving it. Below is a drawn diagram showing the process of osmosis.
pH > 7 is alkalinity environment that will bind hydrogen ion, and pH < 7 is acidic environment that will donate hydrogen ion. On the other hand, increasing hydrogen ion concentration will reduce the bound metal cation concentration. Decreasing hydrogen ion concentration will increase the hydroxyl ion concentration (M. Chaplin, 2004). Enzymes are one of the most efficient catalysts in biochemical reactions. They are used to speed up the reaction rates by providing an alternative reaction pathway of lower activation energy, which is the minimum energy that requires for reactions occur.
Conclusion The mass of the potato gets smaller as you increase the morality of the sucrose solution that it is submerged in. This statement is back by the averages of the percent changed increase of the mass of the potato for the solutions .2M, .4M, .6M, .8M and 1M of sucrose which are 6.98%, -10.79%, -23.38%, -27.78 and -29.83% respectively. Where from the lowest of .2M solution had an increase of 6.98% meaning the solution of sucrose flowed into the potato causing it to expand. While at the highest solution of 1M of sucrose solution the potato decreased in mass by 29.83%. The middle value of the sucrose solution being .6M of sucrose had a decrease of 23.38%, if you just look at those three percentages on a graph it would reveal that it has a decreasing slope, therefore backup my claim that as you increase the Molarity of the sucrose the mass of the potato decreases.
Refrigeration slows food spoilage because the lower temperature slows binary fission. Under optimal conditions with no limiting factors prokaryotes can grow exponentially. 3. Some bacteria can form endospores in response to harsh environmental conditions. An endospore is a chromosome surrounded by a durable wall that can resist desiccation, freezing and boiling water.
Cody Baycroft Mrs. Vance AP Biology pd.3/6 7 October 2011 Effect of Solute Concentration on Water Potential Research Question: Investigate the concept of water potential in relation to the movement of water into or out of a plant cell (potato). This will be researched by immersing potato cores in sucrose solutions (0.0M, 0.2M, 0.4M, 0.6M, 0.8M, 1.0M) and determining the change in mass (in percent) of the cores. Hypothesis: If the solute concentration is increased, then the water potential of solution will have increasingly more negative values. In other words as the concentration of the sucrose solutions becomes more hypertonic than the potato core (the solution has greater solute concentration and lower water potential) the potato will begin to loose mass since water will leave the hypotonic potato core (the core has less solute concentration hence higher water potential) to the hypertonic solution in order to dissolve the sucrose solution. Water potential is the concept used to combine the differences in solute concentration and pressure to predict the direction in which water will diffuse through the living plant tissue and states that the net movement of water will always be from an area of higher water potential to and area of lower water potential.
Question: How do different salinities affect a seeds ability to germinate? 2 pt Hypothesis: I hypothesize that the seeds in a lower salinity will germinate more. 2 points Prediction: If seeds are place in a bag with a lower salinity, then they are going to germinate more than those in a higher salinity solution. 2 points Materials: • • 60 red kidney beans solutions of 0.0% salt (tap water), 0.20% salt, 0.6.0% salt, 1.0% salt, 1.5% salt 5 paper napkins New package • • 5 plastic baggies with holes cut in them for