Egg Diffusion Lab

          In this lab we asked the question, how and why does a cell's internal environment change, as its external environment changes? We found that when the egg is placed in sugar water, it shrunk both in circumference and mass. The solution that the egg was in was hypertonic, meaning that there was a greater concentration of solute outside the egg than inside, so water left the egg to the outside solution to balance the concentration and reach equilibrium.

Class Data: Sugar Water                                                     Percent Change

Group #	3	5	6	Average
% Change in Mass	-48.4	-35.8	-43.12	-42.17
% Change in Circumference	-18.75	-30.5	-9.8	-19.6

We also found that when the egg is placed in deionized water, it grew both in circumference and mass, except for one group. The solution that the egg was in was hypotonic, meaning that there was a lesser concentration of solute outside the egg than inside, so water went into the egg to balance the concentration and reach equilibrium.

Class Data: Control (Deionized Water)                               Percent Change

Group #	2	4	7	Average
% Change in Mass	1.1	0.69	1.74	1.18
% Change in Circumference	6.1	-8.3	8.82	2.21

       
          One group had data that contradicted our hypothesis because, their egg was placed in deionized water, but it shrunk in circumference. Our hypothesis was that the egg would increase in mass and circumference. The egg grew in mass, but its circumference shrunk. This affected the results by changing the average. Also, some possible errors could be that people could have measured the circumference the long way first, then the short way after the experiment. That would have changed the results by making it seem like the egg shrunk in circumference or grew in circumference. Due to this error, in future experiments I would recommend keeping track of which way the egg is measured initially to keep the data accurate.

            This lab was done to demonstrate our understanding of osmosis and diffusion in cells. From this lab I learned the difference between hypertonic solutions and hypotonic solutions and their effects on a cell, which helps me understand the concept of how cells grow and shrink. Based on my experience on this lab, I could apply this knowledge to figure out how to quickly hydrate someone's cells when they are dehydrated. 

          When the sugar concentration increased, the mass and the circumference shrunk because the cell has to take out more water from itself, through the membrane to achieve equilibrium. The cell's internal environment changes as its external environment changes because it has to adapt in order to survive in changing external environment. This lab demonstrates a biological principal I've learned in class by showing that organisms adapt to their surroundings. Water is added to plants in markets to keep them moist. Salt is sprinkled on icy roads to cause the ice to diffuse away and melt into water. Based off of this experiment, I would want to test the affects of salt on ice.