Osmosis in a real cellintroductionin the textbook we learn


Page: 1 of 3 Osmosis in a Real CellIntroductionIn the textbook we learn that the process of diffusion dictates that substances (any type of molecule) will move from a place or point of high concentration to a place or point of lower concentration. For example, if you spray perfume into the air the perfume molecules will be at ahigher concentration at the point of release and will move out from that point. We call the difference between this release point and everywhere around that point as having a gradient and specifically there is a concentration gradient. Molecules will also move across things like membranes by diffusion from a point of high or higher concentration to low or lower concentration. This specific type of diffusion is either called osmosis if the molecule is water or dialysis if the molecule is anything but water. In living cells, survival depends on the ability to maintain homeostasis by regulating the movement of molecules across the cell membrane. In osmosis, water molecules move across a selectively permeable membrane toward a solution with a higher concentration of solutes. The molecules continue to move until equilibrium is reached (that is, equal concentrations of water molecules and of solute molecules on either sideof the membrane). The selectively permeable membrane you will use to study osmosis is the membrane within an eggshell. The shell of the egg is made of calcium carbonate, commonly calledlimestone. When vinegar chemically reacts with the limestone, one of the products is carbon dioxide gas, those bubbles that are seen on the egg. After the reaction, the eggshell will be rubbery and will readily allow water to pass through in response to concentrations of the solutions on either side of the membrane. The water will move toward the more hypertonic, or highly concentrated, solutions because the relative concentration of water is less where there is more dissolved molecules.Materials:YOU MUST HAVE A BALANCE THAT IS ACCURATE TO 0.01 GRAMSRaw egg Karo syrup, undilutedProcedure:1. Determine the mass of a raw egg to the nearest 0.01 g. Record the mass as mass of raw eggand shell in the DATA TABLE. Using the balance I suggested, you need to turn the power on and place a plastic or paper cup on the balance and push the tare button (make sure the mode of grams, "g" in upper right corner.2. Place the egg (after recording the mass to the nearest 0.01 g in enough white vinegar to submerge the egg. Observe and record the changes in the appearance of the egg over the next72 hours.4. After 72 hours, remove the egg with a spoon and rinse it well under tap water. Also rinse the container to remove the vinegar.5. Place the egg on a paper towel and CAREFULLY blot it dry. Find the mass of the egg and record it in the DATA TABLE as mass of egg without shell.6. Place the egg again in the container. Pour water into the beaker so that the egg is completely covered. Wait 60 minutes. Record your observations. 7. Remove the egg from the beaker using a spoon. Place the egg on a paper towel and CAREFULLY blot it dry. Find the mass of the egg and record it in the DATA TABLE as mass of egg after 60 minutes in water.8. Now place the egg again in the container and cover it with Karo syrup. Observe the egg in thesyrup after 60 minutes. Record your observations. Place the beaker and egg in a safe place for 24 hours.9. The next day, remove the egg from the Karo syrup, rinse, and blot. Find the mass of the egg and record it in the DATA TABLE as mass of egg after 24 hours in Karo syrup. Record your observations.10. Data table:Mass of raw egg and shell. ________ gMass of egg without shell. ________ gMass of egg after 60 minutes in water. ________ gMass of egg after 24 hours in Karo syrup. ________ gMass of egg after 24 hours in __________. ________ gQuestion 1. What effect did the acid have on the egg?Question 2. What passive process of moving molecules is demonstrated in this experiment?Question 3. In which instance is the egg in a hypertonic solution?Question 4. In which instance is the egg in a hypotonic solution?Now, propose a testable hypothesis that can be either supported or refuted by an experiment that you will carry out based on the above experiment. So please record a hypothesis and carryout the experiment and record the results in the data table. Remember a hypothesis is a statement that can be tested. For example, The egg will lose mass if it is placed in bleach. Get the point? 

Solution Preview :

Prepared by a verified Expert
Biology: Osmosis in a real cellintroductionin the textbook we learn
Reference No:- TGS01278833

Now Priced at $30 (50% Discount)

Recommended (91%)

Rated (4.3/5)