Diffusion and Osmosis Essay

Diffusion and osmosis are really of import in biological procedure. Diffusion is the motion of molecules or ions from a part of their high concentration to a part of their low concentration. Osmosis is the diffusion of H2O molecules across a semipermeable membrane. To derive a better apprehension of diffusion and osmosis. we examine multiple experiments to demo diffusion and osmosis in animate being cell. works cell and man-made cell. In our first experiment. we weight a decalcified poulet egg and topographic point 10 % NaCl concentration. At every 15 proceedingss intervals. we weight the egg and record that the weight decreases. In our 2nd experiment. we use three pieces of aquatic works Elodea and add pool H2O one foliage. distilled H2O for the 2nd and 20 % NaCl for the 3rd. so observe the cells of each foliage with a compound microscope.

Under microscope. chloroplasts ( green cell organs ) in Elodea tend to jump to the cell wall in pool H2O. spread all over the cell in distilled H2O. draw off from cell wall in 20 % NaCl. In our last experiment. we use a dialysis bag that contains 30 % glucose and amylum solution so topographic point into a beaker of H2O and iodine solution. We so take the bag out of the beaker. and utilize two trial tubing which label BAG. BEAKER to execute a Benedict’s trial. We place solution in the bag in the BAG tubing. and solution in the beaker in the BEAKER tubing and add a bead of Benedict’s reagent to each tubing. so heat each trial tubing and detect a colour alteration in each tubing. These experiments show that motion of H2O of poulet egg cell and Elodea cell is “osmosis” and motion of molecules in dialysis bag and beaker is “diffusion” .


Diffusion is involved in many biological procedures happening in one-celled to complex being ( mention this ) . It is a portion in life that we need to cognize and understand how it works. Diffusion is the procedure by which molecules move from an country of high concentration to an country of low concentration ( mention this ) . A subdivision of diffusion procedure is osmosis. which is the motion of H2O across a membrane which is selectively permeable ( mention this ) . We are traveling to larn and acquire more information about diffusion osmosis by perform three experiments. We place a unshelled poulet egg in salt solution. We predict that H2O in the egg will travel out the cell because this is a hypertonic solution. a greater concentration of osmotically active substance than the solution on the other side of membrane.

Following. we are traveling have three pieces of Elodea in each different solution: hypotonic. isosmotic. hypertonic so we observe these reactions in the microscope. We predict that one will hold chloroplasts ( green cell organs ) edge to cell wall in hypotonic. one will hold chloroplasts move in the cytol. one will hold cell wall remain integral and chloroplasts move off from cell wall. Third. we’re traveling to utilize a dialysis bag contains amylum and glucose and topographic point in H2O and iodine solution. After a Benedict trial. we predict that there will be colour alteration in these solutions. These experiments are easy to execute and they besides give people adequate information to derive better constructs of how diffusion works in animate being cell. works cell. and man-made cell.


First. we performed an experiment to demo osmosis in animate being cell. Our stuffs in this experiment were a decalcified egg. a 350mL beaker. 10 % of NaCl solution. a ternary beam balance. and a timer. We used the ternary beam balance to weigh the egg. The weight of the egg was 77. 3g at this clip. Following. we placed the egg in the beaker that was filled with 250mL of 10 % NaCl. We waited about 15 proceedingss and so take the egg out of the beaker. We dried off the H2O from the egg and placed the egg on the ternary beam balance. The weight of the egg after 15 proceedingss was 76. 6g. We so placed the egg back in the beaker and repeated these stairss every 15 proceedingss intervals. At 30 proceedingss. the egg’s weight was 76. 3g. At 45 proceedingss. the weight was 76. 2g. At 60 proceedingss. the weight was 76. 1g. We recorded the informations and calculated the per centum alteration in egg weight by utilizing the weight at the present clip minus the old weight all over the old clip and all multiply to one hundred. We so graphed our informations to demo percent alterations in weight of the egg.

Following. we performed another experiment to demo osmosis in a works cell. We used foliage of the aquatic works Elodea. pool H2O. distilled H2O. 20 % NaCl solution. a compound microscope. a brace of forceps. First. we cut three little pieces from Elodea works with forceps. We so carefully placed each piece onto the microscope slide glass. We added a little bead of pool H2O to one piece and labeled it “pond water” . We added a little bead of distilled H2O to another piece and labeled it “distilled water” . Last we added 20 % NaCl to the last piece and labeled it “20 % NaCl” . We waited for 10 proceedingss and so we observed the cells of each piece of foliage under the microscope. We so sketched the cells of each piece as seen in the microscope. In our last experiment of diffusion of man-made cell. we used a 30-cm strip of damp dialysis tube. a twine. 30 % glucose solution. starch solution. iodine solution. Benedict’s reagent. hot home base. 500-mL beaker tierce filled with H2O. handled trial tubing holder. 3 standard trial tubing. disposable transportation pipettes. two of 400-mL beakers to keep dialysis bag.

First. we soaked the dialysis tube in H2O and closed one terminal with a twine. and allow the other terminal unfastened. Then we added four pipettesful of 30 % glucose into the bag and four pipettesful of starch solution to the glucose in the bag. We gently mixed the contents and observed the colour in the bag. Following. we add 300mL of H2O to 500mL beaker. We put some beads of iodine solution in the H2O and it turned into a brown colour. After that. we placed the dialysis bag into the beaker and waited for 30 proceedingss. After 30 proceedingss. we moved the bag and allow it stand in a dry beaker. We so recorded the information. Following. we used two trial tubing which labeled “BEAKER” and “BAG” for the Benedict’s trial. We put two pipettesful of the bag solution in the BAG tubing and two pipettesful of the beaker solution in the BEAKER tubing. We added a bead of benedict’s reagent to each tubing and heat them up in hot H2O for three proceedingss. After three proceedingss. we observed the colour alteration and recorded our informations.


In our first experiment with decalcified egg in 10 % NaCl. we find that the weight of the unshelled egg lessenings after every 15 proceedingss clip interval. At clip nothing. the egg has 77. 3g but after 15 proceedingss. the egg has 76. 6. a -0. 9 % alteration in weight. At 30 proceedingss. the egg has 76. 3g. a -0. 4 % alteration in weight. At 45 proceedingss. the egg has 76. 2g. a -0. 1 % alteration in weight. At 60 proceedingss. the egg has 76. 1g. a -0. 1 % alteration in weight.

In our 2nd experiment with Elodea works. we find that chloroplasts ( green cell organs ) of Elodea cell in pool H2O moves near to cell wall. In distilled H2O. we find that chloroplasts ( green cell organs ) of Elodea cell move freely through out in the cytol but block by cell wall. We besides find that chloroplasts ( green cell organs ) of Elodea cell of in 20 % NaCl traveling off from the cell wall and signifier tightly in the cardinal of cytol. In our last experiment with dialysis tubing. we observe some colour alteration. The bag solution. which contains glucose and amylum. has a crystalline original colour. turns to transparent with some black points as concluding colour. After utilizing the Benedict’s reagent. the tubing which contains the bag solution turns into an orange colour.


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