Starch Lab
“Is Starch Permeable in Cells?
Abstract
This report presents the weights of 3 samples of water with various amounts of solute after the use of osmosis. Three different tests were performed, each with a beaker of water containing varying amounts of starch from 30% concentration (12.5 grams of water) to 15% concentration (9.5 grams of water), and then 0% (10.5 grams of water). To start this experiment, we put water into a make-shift dialysis tube, a type of semi-permeable membrane tubing made from regenerated cellulose (Wikipedia). We then tied each end of the dialysis tube with floss, weighed the dialysis tubes and recorded their weights. Next, we made the starch/water solution using the formula: Volume1*Concentration1=Volume2*Concentration2. …show more content…
We put the tubes into the newly formulated solutions one by one, and then we waited 5 minutes, then weighed and recorded our results. Afterwards, we placed them back into the water for an additional 5 minutes and then weighed and recorded the results. The weights of these water molecules are as follows: 13.3 grams (0.8 grams gained) for the 30% solute concentrated solution, 10.0 grams (0.5 grams gained) for the 15% solute concentrated solution, and 10.5 (0 grams gained) grams for the pure water concentration.
Introduction
In the lab “How do I know my artificial cell has a selectively permeable membrane?”, the objective was to determine if the starch molecules were permeable to the cell membrane. If the molecules were permeable, the starch would be able to cross through the membrane into the cell causing the cell to gain weight where they would be either larger or smaller than the phospholipids. In most of these osmosis experiments, the most efficient way to produce new data is to use the data that we already know is correct. The lab had contained three parts. Part A was demonstrated by the TA to show us how the solution will use diffusion to permeate through the DT by putting iodine in the DT and putting it in a solution. After a certain period of time the iodine began to demonstrate diffusion and found it’s way out of the DT and into the solution. Part B was constructed by our lab table and demonstrated the process of osmosis. Part B was meant to evaluate if starch was permeable to the DT. To figure out if starch was in fact permeable we had to find the weight of the DT with water in it before it was placed in a solute concentration and then after a certain period of time had to weigh the DT again and record any weight loss or gain. Then in Part C, diffusion was again demonstrated by doing the same process as Part B. The the process of diffusion is where molecules and ions pass from an area with higher concentration to an area with lower concentration and keeps doing that until a state of equilibrium is reached. A hypotonic cell is when there is more of a solution in a cell than outside of the cell, a hypertonic cell is when there is less solution in the cell than outside the cell, and an isotonic cell is when the cell is in a state of equilibrium (Yahoo). “Osmosis is the passage or diffusion of water or other solvents through a semipermeable membrane that blocks the passage of dissolved solutes” (HowStuffWorks). Scientists use diffusion and osmosis to understand the way in which molecules intermingle as a result of their kinetic energy of random motion (HyperPhysics). There could be multiple possibilities of hypotheses for the question “how do i know my artificial cell has a selectively permeable membrane?”. Such hypotheses as: Will the cell be permeable in water? Is the solution outside the cell hypertonic, hypotonic, or isotonic? Or will a higher concentration be more permeable than a lower concentration? Our hypothesis is the third question “will a higher concentration be more permeable than a lower concentration?”
Materials & Methods
With the given materials, we were able to construct a method to replicate osmosis and figure out the permeability of the artificial cell. Creating solutions we were able find the precise measurements needed to conduct the experiment. Given three types of solutions we conducted different tests to come up with the most accurate results. We took a 400 mL beaker and measured out the amount of distilled water needed from our solution and poured that in.
Results
Concentration
Initial
5 minutes
10 minutes
0%
10.5g
10.5g
10.5g
15%
9.5g
10g
10g
30%
12.5g
13g
13.3g
In two of the three experiments, we noticed that as time increased there was an increase in the weight of the DT (see Figure 1). We can conclude now that starch had been smaller than the phospholipids of the membrane therefore starch was able to permeate through the membrane and into the DT. We can also conclude that the solution outside of the cell is hypertonic because there were more molecules outside of the manufactured cell causing the molecules to shift into the manufactured cell (because of osmosis) in order to balance the concentration. The 30% solute concentration had the greatest gain in weight because this was the hypertonic solution, causing more solution to pass through the membrane allowing the cell to gain weight. The solution with the least increase in weight was our control solution of the 0% solution (pure water). It had a net gain of zero weight because the solution the DT tube was submerged in was isotonic (Figure 2).
Discussion
This experiment demonstrated how a cell can regulate internal homeostasis.
The experimental membrane we used in this lab acted as a barrier in which only a small number of molecules can pass through. In this experiment we wanted to show the process of osmosis, in which water passes through the aforementioned barrier. Osmosis is critical to life because the process regulates the amount of water in the cell, in turn regulates the concentration of all of the molecules and ions within the cell. The hypothesis we tested was that the cell with the higher concentration of solute (30%) will allow more water to pass through the membrane than that of the cell with a lower concentration (15%). This in turn will result in the 30% solute concentrated cell being the heaviest compared to the 15% solute concentrated cell (second heaviest) and pure water. The pure water was our negative control variable, meaning that the manufactured cell in the water would show zero weight gain. Our results concluded that our hypothesis was well founded and accurate. The results are here as follows: the negative control (pure water) had zero weight gain, the middle concentration gained a total of .5 grams and the high concentration gained a total of .8 grams. Due to a lack of exact weight controls in our initial weight values and the fact that we had only conducted one experiment, there’s potentially a lack of correlation between the percent concentration and weight gained in the
cell.
A cell is kept alive by the passage of water through its semi-permeable membrane. The semi-permeable membrane of a cell that allows water to pass through it is what keeps the cell alive. For a cell to maintain a state of equilibrium the cell goes through a hypotonic or hypertonic interaction which had been demonstrated in the experiment. If a cell cannot perform these interactions and is without a membrane that allows the flow of water, the cell will die. The cell could either stay in a hypotonic state where the cell will become over capacitated and explode because of osmotic shock, or the cell will stay in a hypotonic state where there is not enough water and shrivel up and die.
The results had shown that the manufactured cell that had a 30% solute concentration and a beginning weight of 12.5 grams, had a total gain of .8 grams of water. The manufactured cell with 15% solute concentration and a beginning weight of 9.5 grams, had a total gain .5 grams of water. Then the manufactured cell that was our negative control with a 0% solute concentration and a beginning weight of 10 grams gained zero grams of water. The cell with the higher solute concentration demonstrates a hypertonic reaction where the cell absorbing water to balance the concentration in the manufactured cell. The cell is only alive because of the crucial process of osmosis to keep the cell in a state of equilibrium.
Abstract
This report presents the weights of 3 samples of water with various amounts of solute after the use of osmosis. Three different tests were performed, each with a beaker of water containing varying amounts of starch from 30% concentration (12.5 grams of water) to 15% concentration (9.5 grams of water), and then 0% (10.5 grams of water). To start this experiment, we put water into a make-shift dialysis tube, a type of semi-permeable membrane tubing made from regenerated cellulose (Wikipedia). We then tied each end of the dialysis tube with floss, weighed the dialysis tubes and recorded their weights. Next, we made the starch/water solution using the formula: Volume1*Concentration1=Volume2*Concentration2. …show more content…
We put the tubes into the newly formulated solutions one by one, and then we waited 5 minutes, then weighed and recorded our results. Afterwards, we placed them back into the water for an additional 5 minutes and then weighed and recorded the results. The weights of these water molecules are as follows: 13.3 grams (0.8 grams gained) for the 30% solute concentrated solution, 10.0 grams (0.5 grams gained) for the 15% solute concentrated solution, and 10.5 (0 grams gained) grams for the pure water concentration.
Introduction
In the lab “How do I know my artificial cell has a selectively permeable membrane?”, the objective was to determine if the starch molecules were permeable to the cell membrane. If the molecules were permeable, the starch would be able to cross through the membrane into the cell causing the cell to gain weight where they would be either larger or smaller than the phospholipids. In most of these osmosis experiments, the most efficient way to produce new data is to use the data that we already know is correct. The lab had contained three parts. Part A was demonstrated by the TA to show us how the solution will use diffusion to permeate through the DT by putting iodine in the DT and putting it in a solution. After a certain period of time the iodine began to demonstrate diffusion and found it’s way out of the DT and into the solution. Part B was constructed by our lab table and demonstrated the process of osmosis. Part B was meant to evaluate if starch was permeable to the DT. To figure out if starch was in fact permeable we had to find the weight of the DT with water in it before it was placed in a solute concentration and then after a certain period of time had to weigh the DT again and record any weight loss or gain. Then in Part C, diffusion was again demonstrated by doing the same process as Part B. The the process of diffusion is where molecules and ions pass from an area with higher concentration to an area with lower concentration and keeps doing that until a state of equilibrium is reached. A hypotonic cell is when there is more of a solution in a cell than outside of the cell, a hypertonic cell is when there is less solution in the cell than outside the cell, and an isotonic cell is when the cell is in a state of equilibrium (Yahoo). “Osmosis is the passage or diffusion of water or other solvents through a semipermeable membrane that blocks the passage of dissolved solutes” (HowStuffWorks). Scientists use diffusion and osmosis to understand the way in which molecules intermingle as a result of their kinetic energy of random motion (HyperPhysics). There could be multiple possibilities of hypotheses for the question “how do i know my artificial cell has a selectively permeable membrane?”. Such hypotheses as: Will the cell be permeable in water? Is the solution outside the cell hypertonic, hypotonic, or isotonic? Or will a higher concentration be more permeable than a lower concentration? Our hypothesis is the third question “will a higher concentration be more permeable than a lower concentration?”
Materials & Methods
With the given materials, we were able to construct a method to replicate osmosis and figure out the permeability of the artificial cell. Creating solutions we were able find the precise measurements needed to conduct the experiment. Given three types of solutions we conducted different tests to come up with the most accurate results. We took a 400 mL beaker and measured out the amount of distilled water needed from our solution and poured that in.
Results
Concentration
Initial
5 minutes
10 minutes
0%
10.5g
10.5g
10.5g
15%
9.5g
10g
10g
30%
12.5g
13g
13.3g
In two of the three experiments, we noticed that as time increased there was an increase in the weight of the DT (see Figure 1). We can conclude now that starch had been smaller than the phospholipids of the membrane therefore starch was able to permeate through the membrane and into the DT. We can also conclude that the solution outside of the cell is hypertonic because there were more molecules outside of the manufactured cell causing the molecules to shift into the manufactured cell (because of osmosis) in order to balance the concentration. The 30% solute concentration had the greatest gain in weight because this was the hypertonic solution, causing more solution to pass through the membrane allowing the cell to gain weight. The solution with the least increase in weight was our control solution of the 0% solution (pure water). It had a net gain of zero weight because the solution the DT tube was submerged in was isotonic (Figure 2).
Discussion
This experiment demonstrated how a cell can regulate internal homeostasis.
The experimental membrane we used in this lab acted as a barrier in which only a small number of molecules can pass through. In this experiment we wanted to show the process of osmosis, in which water passes through the aforementioned barrier. Osmosis is critical to life because the process regulates the amount of water in the cell, in turn regulates the concentration of all of the molecules and ions within the cell. The hypothesis we tested was that the cell with the higher concentration of solute (30%) will allow more water to pass through the membrane than that of the cell with a lower concentration (15%). This in turn will result in the 30% solute concentrated cell being the heaviest compared to the 15% solute concentrated cell (second heaviest) and pure water. The pure water was our negative control variable, meaning that the manufactured cell in the water would show zero weight gain. Our results concluded that our hypothesis was well founded and accurate. The results are here as follows: the negative control (pure water) had zero weight gain, the middle concentration gained a total of .5 grams and the high concentration gained a total of .8 grams. Due to a lack of exact weight controls in our initial weight values and the fact that we had only conducted one experiment, there’s potentially a lack of correlation between the percent concentration and weight gained in the
cell.
A cell is kept alive by the passage of water through its semi-permeable membrane. The semi-permeable membrane of a cell that allows water to pass through it is what keeps the cell alive. For a cell to maintain a state of equilibrium the cell goes through a hypotonic or hypertonic interaction which had been demonstrated in the experiment. If a cell cannot perform these interactions and is without a membrane that allows the flow of water, the cell will die. The cell could either stay in a hypotonic state where the cell will become over capacitated and explode because of osmotic shock, or the cell will stay in a hypotonic state where there is not enough water and shrivel up and die.
The results had shown that the manufactured cell that had a 30% solute concentration and a beginning weight of 12.5 grams, had a total gain of .8 grams of water. The manufactured cell with 15% solute concentration and a beginning weight of 9.5 grams, had a total gain .5 grams of water. Then the manufactured cell that was our negative control with a 0% solute concentration and a beginning weight of 10 grams gained zero grams of water. The cell with the higher solute concentration demonstrates a hypertonic reaction where the cell absorbing water to balance the concentration in the manufactured cell. The cell is only alive because of the crucial process of osmosis to keep the cell in a state of equilibrium.