Conclusion The main purpose of this experiment was to determine the effect of changing molarities on diffusion of water molecules. The claim made was that the net direction of water is affected by water potential and solute potential. It was also predicted that as the sucrose solution molarities increased, the % change in the mass of the dialysis bag would increase and the change in the potato cores would be negative. The control group for the experiment was the dialysis bag and potato cores that were immersed in distilled water. Because the experiment was based on the change in molarities, distilled water was a good control because distilled water is pure and has no concentration of any solution. The experimental groups for this experiment were the dialysis bag and the potato …show more content…
These were the experimental groups because their solute concentrations and membrane permeability were very different and were able to show the two different reactions of osmosis comparing when the environment is hypertonic or hypotonic to the object. In the dialysis bag, the % change in mass at distilled water was positive and very high. As the molarity of the solution increased, the % change in mass also increased. In the potato cores, the % change in mass for the control of distilled water was very high at almost 20%. However, as the molarity increased, the % change in mass was negative and increasing. There were 9 total trials for the dialysis bag experiment and 6 trials for the potato cores. These multiple trials made it easier to spot out outliers and make sure the data was accurate. Some of the trials had to be left out of the data because they
In conclusion, the objective of the experiment was met since the process of osmosis was observed and
Specific to the experiment, the distillation technique will be used to separate the two miscible liquids, conclude their identities based on the boiling points
Factors Affecting the Rate of Osmosis I. Research Question: How does the amount of Monosodium glutamate or MSG (C5H8NO4Na) concentration affect the osmosislarity of cow (Bos taurus ) liver cells? II. Background information Osmosis is the diffusion of water molecules through a partially permeable membrane from a region of high water concentration to a region of low water concentration. The factors affecting the rate of osmosis are temperature, concentration gradient, molecular size, surface area to volume ratio, and permeability. Animal liver cells, such as cow liver cells have a nucleus, cytoplasm, and a cell membrane.
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.
Three trials has been done for this experiment. For Trial 1, Trial 2 and Trial 3, the apparent mass for each trial are 99.330g, 99.261g and 98.741g respectively. After calculation, the true mass has been obtained and for each trial, the mass recorded are 99.449g, 99.380g and 99.859g respectively. As the temperature for all trial is 24.0˚C, the density of water being recorded is 0.997296g/ml. Finally, the actual volume of water being transferred after calculations are 99.717ml, 99.649ml
The dialysis experiment did not concur with the original hypothesis that all of the substances would be able to pass through the dialysis tubing into the surrounding water in the beaker. Sodium chloride and sugar did pass through the membrane while starch, was not able to pass through (fig. 7). These results show that sodium chloride and glucose (sugar) are small enough molecules to permeate the membrane, but starch is a much larger molecule and therefore was not able to get through. This is understandable because starch has a much higher molecular weight than the other two
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.
The Gummy Bear experiment illustrates osmosis, a type of diffusion involving the movement of water molecules through a semi-permeable membrane. The gummy bear represents the semi-permeable membrane. The area inside of the gummy bear had a higher solute concentration than the area outside of the gummy bear, so the water was moving. In situations like this, water tries to move from an area of high water concentration (or low solute concentration) to an area of low water concentration (or high solute concentration). The water moves around until it achieves an equilibrium.
This experiment was created to contrast the effects of osmosis between three gummy bears in tap, sugar, and salt water. To compare the gummy bears, three cups were gathered and filled with twenty-five milliliters of the particular water solution. Then the mass and volume of each gummy bear was recorded into a chart. To find the mass, zero a balance once a strip of wax paper is placed over, and then place your gummy bear and record the mass. To find the volume of the bear, multiply the length, width, and height of the bear in centimeters with the help of a ruler.
INTRODUCTION: In this experiment I was testing for antimicrobial sensitivity of Staphylococcus epidermidis by using the Kirby-Bauer Diffusion test. The three antibiotics utilized in this lab were: gentamicin, novobiocin, and penicillin. I determined the effectiveness of the antibiotic by observing and measuring the zone of inhibition for each antibiotic.
Diffusion and Osmosis Lab Report By: Jettica Williams BIOL 1107 Lab September 21, 2016 Prepared for Mrs. Fulford Lab Course Page Break The cell membrane act as a roadblock for cells. The cell membrane has a very hectic job. It restricts the access to what comes in and what goes out. The bond the membrane shares with others is the idea of accountability.
Diffusion and osmosis are directly related by that they are the movement of molecules from a high concentration to a low concentration. The main difference being that osmosis is a special kind of diffusion in which water is the solvent and moves from a high water concentration to a low water concentration through a semipermeable membrane. Diffusion and osmosis is vital to living organisms as it is the process by which useful nutrients and other molecules enter the body cell and waste products, from processes such as respiration, are removed. Part A of our lab was meant to show the process of osmosis using cornstarch and iodine. We placed a plastic bag filled with starch and water into a beaker filled with water and iodine.
Within the lab of observing passive transport, it had been apparent that only two different types of transport had been used. Both diffusion and osmosis are involved in the movement of substances from an area of high concentration to an area of low concentration. They will both continue to happen until an equilibrium is reached, at which time there will be no net movement of substances. Diffusion does not require a membrane to occur and it involves a variety of different molecules.. Osmosis, on the other hand, involves the movement of water molecules from a region where they are in high concentration (hypotonic solution) to a region where they are in lower concentration (hypertonic solution) across a semipermeable membrane.
In this experiment, it was observed how the amount of salinity in water affected the mixing of two types of water. During this experiment, two flasks were filled with water and then ten grams of salt and one drop of food coloring were added to one of the flasks. Then an index card was put onto the top of the flask with salt water to keep the water inside the flask and placed on top of the fresh water flask. The index card was then slid out and the two types of water solutions began to mix. This was repeated two more times, one with the fresh water on top and another with the flasks going horizontally.
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).