Starch solution is then placed into the test tube at a quantity of 5 mL. 5 drops of Lugol’s Iodine solution is added to the test tube. If the color changes, then it is known that starches are present in the solution. Proteins are next tested. In order to do this, 5 mL of gelatin solution is added to the test tube. 10 drops of Biuret’s reagent are added to test for protein.
The egg contained more water than the solution which made it hypertonic. The water moving out of the cell transferred to the solution which caused it to be smaller. Which solutions caused water to move into the egg? Explain and cite evidence. The solutions that caused the water to move into the egg were the vinegar and distilled water.
Additionally, it was difficult obtaining a piece of rhubarb that was thin and particularly red, therefore the effect could not be best observed in the cells. Part B: Design your own experiment Parts of this practical were taken and slightly altered from the following link http://www.markedbyteachers.com/gcse/science/investigate-the-effect-of-surface-area-on-osmosis-in-potato-tissue.html Aim: To observe the effect different surface area: volume ratios have on osmosis in potato tissue. Hypothesis: If the potato has a larger surface area: volume ratio, the quicker osmosis will take place and the larger the mass will be at the end of the experiment, therefore the difference in mass of the potatoes from the start of the experiment to the end of the experiment will be larger. Additionally, the potato pieces left in a saltwater solution will decrease in mass, whereas the pieces left in water will increase in mass.
When the eggs were just placed in 200 mL of water, their masses greatly increased. The inside of the eggs have a higher solute concentration than the water outside the cell. Water
In the process of diffusion, the molecules move from an area of low concentration to an area of high concentration. The process worked as the concentration of salt was higher compared to the concentration of the cells in the potato which was lower. The skin of the potato acted like a semi-permeable membrane. As there was some water content in the cells of the potato, to achieve equilibrium with the salt, the water had to be absorbed by the salt through the process of osmosis. As a result, one qualitative observation at the end of the lab was that there was a lot of water content outside of the potato compared to the start when the petri-dish was completely dry.
The egg was a peril white egg in the beginning to a blue splat egg in the end. Starting on Day 0, October 17, was a small, narrow, and white egg with the circumference of 140 mm. On that same day, I let the egg soaked in vinegar for a total of two days. On Day 1, the circumference of the egg was 150mm. The egg was 10mm bigger, squishy, and had a dissolved shell.
They really saw how the cell was semi permeable because it allowed the water to leave and enter the cell during different situations. The question that had to be answered on Day 1 was what happened to the egg cell after it was put in vinegar. The hypothesis was proven correct because the egg cell shell was eaten away at by the acidic vinegar since the circumference grew by 13mm. The shell was really soft. If it was in there a little longer that the shell would eventually disappear.
Also, the pictures above show how the egg changed from being tight and solid to being flexible. The observations also say that the egg felt like a water balloon and was full of water inside. Overall, the egg greatly shrunk in size. Finally, when the egg was placed in corn syrup, it floated on the surface of the solution. This was because the egg floated in solutions hypertonic to its inside.
2. The nobleman assumed that Columbus would not break the egg for it to stand on one end; he rather expected the egg to remain whole. Therefore, he was reassured that
Purpose/Question This lab was made to find out what the possible methods are, such as sand in a plastic container with a piece of black polyethylene foam inside the lid, to protect an egg from a two meter drop on a hard floor. What effect does a container of sand have from a two meter drop on a hard floor with an egg halfway buried inside the sand? Background
For this lab I will be using water and sucrose to demonstrate the rate of osmosis. In this lab I will be exploring how temperature impacts the rate of osmosis by placing pieces of potato of equal size in solutions of different temperatures and observing the change in mass of potato after a given period of time. The change in mass will indicate the rate of osmosis.
In this practical agar jelly cubes will be used to represent a cell. AIM: To model diffusion in a practical form and investigate the effect of surface area to volume ratio. HYPOTHESIS: It is hypothesised the smaller the cube the quicker and bigger the rate of diffusion will be and with a larger cube there will be a smaller percentage of diffusion due to its bigger volume.
By using the same mass of potato slices and putting them in different concentration of solutions for a specific amount of time will tell us how the concentration changes the mass of the potato slice. Therefore changing the rate of osmosis. Hypothesis: I predict that, if the piece of potato was put into a solution that has a high concretion of sucrose then the potato slice would lose mass as it would lose water from its cells because the water is moving out of the cell from a high concentration to a low concentration of water through a semi- permeable membrane. The cell is hypotonic and the solution is hypertonic.
Think of it like this, adding salt to the water makes it like an ocean which is easier to float and swim in than just normal/ distilled water. This is because salt makes water denser. When salt water gets denser, the easier it would be for objects to float on it. My hypothesis was correct. The water did go inside the egg, but the ones with least salt increased the most, unless the egg was the smallest and it had enough space to take in a lot of extra water.
Biology Design Practical Joshua Edwards What are effects of the volume of a potato and the amount of weight it loses when placed in salt solution? Introduction This design practical uses a potato’s surface area to volume ratio to see what affects it has on osmosis in different concentrations. Osmosis is the movement of water molecules through a cell membrane into an area of a higher solute concentration. The movement goes the way of the solvent with more solute because the lower solute concentration is drifting through balancing the ratio of solute per solvent (En.wikipedia.org, 2018).
