4. Also it helps the students to understand how yeast works and reacts to different chemicals. * Is important to shake the yeast suspension just before you add some to the test tube because all the yeast is in the bottom and you need to get it to the top to get them to the tube. * My graph shows that the amount of food and the activity of yeast were different because we put different amount of yeast. * The test tube should be set up in exactly the same way except for the differences amount of molasses because if not they would be a different result in the lab.
3. How will the concentration of sucrose in water affect the amount of water that diffuses into or out of the potato cells and thereby change the mass of the potato cells? Hypotheses: 1. If the solution inside the dialysis tubing is hypertonic to the water in the beaker, then the glucose will diffuse out of the bag, and the water will diffuse into the bag, however the starch will remain in the bag. 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.
The first simulated cell will be 1% sucrose solution placed into a 1% sucrose solution. I believe this simulated cell will show us the isotonic part of this lab. I do not think this simulated cell will change in size due to the fact that the simulated cell and the solution it is being placed in are both equal. Therefore, no exchange in water will happen. The second simulated cell will be 1% sucrose solution placed into a 50% sucrose solution.
The bilayer is selectively permeable which enables it to act as a barrier that keeps proteins, ions and other molecules where they are needed and prevents them from diffusing into areas where they are not (Wisegeek.com/bilayer. 2011). Small molecules can move through the layer automatically, this is diffusion from a high concentration to an area of low concentration, whereas water diffuses from highly concentrated areas to low concentrated areas. This process is known as osmosis and its purpose is to maintain equilibrium within the cell in order for it to function properly (Wisegeek.com/bilayer. 2011).
Conditions that must remain constant in this experiment include the temperature of the water baths and the volume of peas and beads in the respirometers. The general gas law states that if temperature and volume remain constant, then the pressure of the gas will change in proportion to the number of molecules of gas present. 2. Water moves into the respirometer pipettes because as oxygen is consumed by the peas, the pressure within the pipettes will decrease and thus the negative pressure will draw the water into the pipette. It is important to correct the readings from the peas because the glass beads are used as a control in which no changes should occur in CO2 and oxygen levels due to their abiotic nature.
Experiment Colligative Properties & Osmotic Pressure Karen Curry 1/19/2014 1:00pm Abstract The purpose of this experiment is to understand and compare the difference of the freezing points between pure solvents in a solution and a non-volatile solute. Secondly, osmosis is demonstrated in a permeable membrane in this case a dialysis tubing and a less permeable membrane with a much harder shell like the egg. Experiment and Observation Starting with Part I of this experiment I gathered together all my items I needed. Small rubber band, salt, tap water, distilled water, 1/8 teaspoon measuring spoon, crushed ice, beaker 100 mL plastic, stopwatch-digital, test tube 13 x 100 mm, digital thermometer, well plate-24. First I made a water bath by filling the 100 mL beaker with cool tap water.
Lab 5: Osmosis Purpose The purpose of this lab is to familiarize you with osmosis and, specifically, what happens to cells when they are exposed to solutions of differing tonicities. Hypothesis Since the 1% sugar solution is being placed into the same type of environment (1% sugar solution), the result should be no change in weight of the simulated cell. However, when the 1% sugar solution is placed into a 50% sugar solution environment, the cell will shrink in size because of the hypertonic tonicity; the water will rush out of the cell to create equilibrium through osmosis, resulting in the shrinkage of the cell. On the contrary, when a 50% and a 20% sugar solution are placed onto an environment of 1% sugar solution, respectively, the cells will bloat up and explode (possibly not in this experiment depending on the strength of our tubing) due to the hypotonic tonicity; the water from the 1% sugar solution will rush into the cell to create an equal amount of solute-to-solution ratio inside, and outside, of the cell. Materials & Methods Materials: · Scale · 4 6” Dialysis Tubing · 4 Transfer Pipets · Sugar · Scissors · Rubber Bands · 4 Same-Sized Coffee Cups · 250ml Graduated Cylinder · Tape Measure · Sauce Pan · 3 600ml Containers · Plastic Covering · Spoon Methods: 1.)
Student's Name: Kwame Owusu Date of Experiment: 0113112015 Date Report Submi*ed: A?l0]ll2}15 Title: Colligative Properties and Osmotio Pressrire purpose: The experiment is meant to caiculate the rnolecular mass of a compound and also tube' The demonstrate how osmosis occur through a semipermeable membrane like a dialysate purpose is also to compare both the freezing afld the boiling point to a control solvent of a solution. procedure: I used a light syrup in a dialysis tubing to calculate the mass in relation to time' 1 also or a nonvolatile used ice chips to determine the freezing point and the boiling point of a tap water solute. Data Tables: Exercise 1: Colligative Properties: Osmosis Data Table 1. Dialysis Tubing Results Time: 0 minutes 30 minutes Mass of Dialysis Tubing i 1.6 grarns 13.3 grams 16.5 grams 60 rninutes Questions: A. The light syrup in the dialysis tubing is hypotonic to the water.
However, will label test tubes with correct Molarities so no confusion occurs. | Dependent- % change in mass | % | Will not control since want to see
Since the membrane has a non-polar layer in its centre and two polar layers on either side, it is difficult for both polar and non-polar molecules to pass through both layers. The bilayer also contains proteins (almost 70%), namely integral and peripheral ones. The main function of the integral proteins is to facilitate the exchange of materials within the cell – one of which is diffusion, which is defined as the movement of substances from a region of higher concentration to a region of lower concentration. The purpose of this experiment is to find out the effect of varying temperature on the permeability of the cell membrane which is to be tested using a beetroot core immersed in water of different temperature and then, using spectrophotometry, finding the absorbance and transmittance percentage of the pigment that is left over. The red pigment present in beetroot (that was mentioned above) is Betalain, a water-soluble (thus making the pigment is suitable for diffusion into an aqueous environment) glycoside with some or all of the sugar groups removed.