After completing this experiment, our tap water hypothesis was correct, and our saltwater hypothesis was also proven. For the tap water, the gummy bear expanded as we thought it would. This was because of osmosis. The water outside of the bear diffused into the bear from the higher concentration outside into the lower concentration inside of it. The gummy bear was a selectively permeable membrane. This made a hypotonic solution, and the water rushed into the bear, making it get bigger. For the salt water, the bear shrunk as we predicted, also because of osmosis. This was a hypertonic solution, so the water rushed out of the bear, making it smaller. So our hypothesis for both tap and salt water were correct. We carried out the experiment properly
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
Take one view of the Onion root tip and count how many cells you see for each stage (you have to see ALL stages – ‘0’ is not an option – switch views if you cannot find all stages).
During osmosis, solvents move across a semipermeable membrane in order to regulate the solute balance within the cell (Campbell Biology). Experiment 5.5 was conducted to further research osmotic activity, particularly in potato cells in different osmolarities of a NaCl solution. The goal of the experiment was to find out whether the potato slices used would be hypotonic or hypertonic to the different osmolarities. This process is relevant because without osmosis, the passage of solvents would not be possible. To perform the experiment, seven potato slices were soaked in 5cm of a different osmolarity level of a NaCl solution (0M – 0.6M) to determine whether each slice was hypotonic or hypertonic to the NaCl solution it was placed in, based on percent weight change. The prediction that the potato slices soaked in solutions with lesser osmolarities (0M – 0.1M) of NaCl would be hypotonic to their solutions, and the potato slices soaked in solutions with higher osmolarities (0.2M – 0.6M) would be hypertonic to their solutions was supported by this experiment because the slices soaked in (0.2M – 0.6M) had
The cell membrane (Plasma membrane) functions to provide cell support, cell stability and control entry and exit of materials from the cell. This study was conducted to test the effects of environmental conditions such as the on beet root cell membrane (Beta vulgaris). Five trials using varied pH concentrations were tested and absorbance rates were monitored. The experimental results showed that the protein function decreased sequentially when the pH decreased. This allowed the betacyanin dye to leak out which created the color that was needed to determine the intensity and therefore the effect of the circumstances. This supported the hypothesis that the more acidic or basic the environmental condition around the beet cell, the more permeable the, membrane indicated by color intensity. Pigment leakage in the solution was analyzed by using a spectrophotometer.
Despite its importance osmosis may also damage cells by causing them to; a) shrink from water loss or b) burst from too much water gain. Plant cells [fig 3] have adapted themselves to ensure that these factors do not affect them, by forming a ridged wall, known as the cell wall, around their cells. The cell wall maintains the shape of the cell, and prevents the cell from bursting in a hypotonic medium by resisting water pressure. Plant cells have also adapted a larger vacuole, which occupies 80% or more of the cells cytoplasm (Davidson, 2004); allowing plants to store more water and nutrients per cell. Vacuoles also play a structural role in plant cells; by swelling when liquids contact them, plant vacuoles are able to control turgor pressure within the cell. This helps maintain the structural integrity of the cell as well as providing the plant with suitable amounts of water and nutrients; however the cell will never burst because the vacuole is contained within the cell wall. If plant cells are deprived of water their vacuole will begin to shrink, yet due to the cell the wall, the plant cell will be able to maintain its shape. [fig.4] Animal cells [fig 5] on the other hand do not have this
Plants need specific conditions to grow. In this experiment plant will be put in hypertonic solutions. Three out of the six plant will be watered with a salt and water solutions. Watering the plants in the solution will place them in a hypertonic solutions, making the water leave the cells to diffuse (in this case) the salt. “Photosynthesis is the process in which plants use water, carbon dioxide, and light energy to make glucose and oxygen.”(PHOTOSYNTHESIS). If water is needed for
Plant cells react differently to osmosis than animal cells. When an animal cell is placed in a hypertonic solution, water will leave the cell causing it to shrink, this is known as crenation. When a plant cell is placed in a hypertonic solution the cell membrane will pull away from the cell wall, making the plant flaccid, this is known as plasmolysis. When an animal cell is placed in a hypotonic solution, water will rush in to the cell, causing it to swell and sometimes burst. A plant cell placed in a hypotonic solution will also swell due to water rushing in, but will resist rupturing due to the rigid cell wall. Plant cells become more rigid in a hypotonic solution.
Van’t Hoff’s Law suggests that the osmotic potential of a cell is proportional to the concentration of solute particles in a solution. The purpose of this experiment was to determine if there are any differences between the osmolalities, the no-weight-changes of osmolalities, and the water potentials of potato cores in different solutions of different solutes. The percent weight change of the potato cores was calculated through a “change in weight” method. The potato core’s weight was measured before and after they were put into different concentrations of a solute for 1.5 hours. In our experiment, there were no significant differences from the osmotic potentials of our results and the osmotic potentials of other scientists work. Ending with chi square values of 2.17 and 2.71, and p values of 0.256 and 0.337, concluding that there is no difference in water potentials of potato cores in different solutions of different solutes at varying concentrations.
Those three experiments showed that the way onion cells are dealing with the movement of water in and out of the cell is by osmosis. That Osmosis is the diffusion of water across a membrane into a solution having a greater solute concentration. The cell
Finally, it could also be a hypertonic solution which is when there is a higher concentration of solute in the solution than in the cell and therefore the water leaves the cell. This make the cell plasmolyzed or “shrunken”. In our experiment this means that the potato cell would
The results from the experiment have shown that an increase in sodium chloride solution increases the rate of osmosis and diffusion until the percentage reaches an amount that is near the concentration of solutes inside the eggs membrane.
The purpose of this lab is to test the effect of osmosis on cucumber slices. If a cucumber slice is placed in a hypertonic solution, then the mass of the cucumber slice will decrease. Whereas, if
1. The epidermal layer of an onion is scaled off carefully and placed on a drop of distilled water on the glass slide;
In this lab we are going to discovery how osmosis works using a semi-impermeable membrane a potato slice. Osmosis is known as the movement of water in and out of a cell. To understand how this works we must understand two terms. Hypotonic means the environment has less solutes compared to the inside of the cell. Hypertonic means that the environment has more solutes compared to the inside of the cell. With osmosis water will always move from hypotonic too hypertonic. So the question is will water move into the potato or out of the potato? Will these results change when placed in different morality of salt water? To calculate these results, we will measure the mass of potatoes cut into equal sizes then soak these potato slices in different morality of NaCl for thirty minutes and measure the mass change in each potato slice.