Osmosis with Eggs PDF

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observation of osmosis with deshelled eggs...

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The Naked Egg

--Naked Egg in Isotonic Solution

Biology 2107 Lab Report #2 Hiba Kausar

An Observation of Osmosis Introduction Osmosis occurs with the net diffusion of water molecules from an area of low concentration to an area of high concentration, across a selectively permeable membrane. It is an integral process for living organisms and their cells. In plants, osmosis is used to absorb soil water and nutrients from the hairs on their roots and then to elevate it to their leaves. Osmotic regulation allows plant cells to retain their turgid shape for optimal function. In the same way, it allows red blood cells in animals to retain their disc shape. We hypothesized that “deshelled” eggs would mimic cells when placed in sucrose solutions of different concentrations across a specified timeline and demonstrate the osmotic movement of water molecules through weight gain or loss. Materials and Methods Six “deshelled” eggs were obtained, weighed and placed in dishes containing different concentrations of sucrose solution; 0%, 10%, 20%, 30%, 40% and unknown (Shanholtzer, 2018). This step was repeated every 15 minutes for a time limit of 60 minutes. At every interval, the eggs were cleaned off to remove any excess solution before being weighed. The weights of the eggs were recorded at zero minutes, 15 minutes, 30 minutes, 45 minutes and 60 minutes. Results We recorded the weights of the eggs in the following table (table 1) for different concentrations of sucrose solutions at the specified time intervals. Time (minutes )

Weight of Eggs (g) Deionized 10% water/ 0% Sucrose Sol. sucrose sol

20% Sucrose Sol.

30% Sucrose Sol.

40% Sucrose Sol.

X Sucrose Sol.

0 15 30 45 60

96.1 99.17 100.76 101.68 102.55

113.84 114.88 115.71 116.38 116.94

90.72 90.71 90.73 90.74 90.86

75.3 74.73 74.13 73.59 73.23

90.37 89.22 88.24 87.24 86.61

87.84 88.18 88.36 88.51 88.76

Table 1: Weights of “deshelled” eggs placed in different sucrose concentrations at 15-minute intervals for a total of 60 minutes, showcase an increase and/or decrease in weight. Weight change (g) of Eggs in different Solute Concentrations at various times (m) 120 113.84 115

115.71

116.38

116.94

100.76

101.68

102.55

90.71

90.73

90.74

90.86

89.22 88.18

88.24 88.36

87.24 88.51

88.7686.61

74.73

74.13

73.59

73.23

15

30

45

60

114.88

Weight Change of Eggs (g)

110 105 100 96.1 95 90.72 90 90.37 87.84 85 80 75.3 75 70 0

99.17

DI H2O 10% Sucrose Sol 20% Sucrose Sol 30% Sucrose Sol 40% Sucrose Sol X Sucrose Sol

Reaction time (Minutes) Figure 1: The weight change of eggs from different concentrations of sucrose solution as plotted again the time of the weight change

The total change of weight of the eggs was calculated by subtracting the weight at the different time interval from the initial weight at time zero (Shanholtzer, 2018). The results were formulated into the following table (table 2). Weight of Eggs (g) Time of weight change (minutes) 0

Deionized water 0

10% sucrose 0

20% sucrose 0

30% sucrose 0

40% sucrose 0

Unknown

15

3.07

1.04

-0.01

-0.57

-1.15

0.34

30

4.66

1.87

0.01

-1.17

-2.13

0.52

45

5.58

2.54

0.02

-1.71

-3.13

0.52

60

6.45

3.1

0.14

-2.07

-3.76

0.92

0

Table 2: results show the change of weight for eggs from different sucrose concentrations at 15-minute intervals

Discussion The 60 minutes time interval was chosen to depict a standard curve of how concentrations of different solutions affected the weight gain or loss of that egg at one specific point in time. Percent concentration (%) of Sucrose Solution 0

Total weight change of Eggs(g) 6.45

10

3.1

20 30

0.14 -2.07

40

-3.76

X 0.92 Table 3: results show the total weight change of Eggs at different concentrations of sucrose solutions at 60 minutes Total weight change (g) of an Egg in different Solute concentrations at time 60 (m) 8 6.45

Total Wweight Change (g)

6 4

3.1

2

0.92 0.14

0 -2.07 -2 -3.76 -4 -6 0

10

20

30

40

X

Percent Concentration (%) Fig ure 2: the total weight change of different concentrations of sucrose solutions at 60 minutes

Figure 2 shows that the isotonic was projected to be 20% (orange line) and the solution with unknown concentration was determined to be 18% (green line).

Our hypothesis of “deshelled” eggs mimicking the osmotic behavior of cells and showcasing the net movement of water molecules against different concentrations of a solute in a solution(osmosis) was supported by the changes in weight of the eggs. The eggs gained weight in a solution of low sucrose concentration, where the water molecules moved from the solution across the egg’s selectively permeable membrane into the egg. In the same manner, the eggs appeared to have lost weight after being placed in a hypertonic solution and water molecule moved out of them into the sucrose solution. There was not much net movement of water molecules in and/or out of the eggs in the isotonic solution, as the weight fluctuated minutely. Some errors may have occurred; recording weight measurements incorrectly, inconsistent sizes and initial weights of all of the six eggs which impaired the ability to compare results precisely, and the fact that they were placed in an acidic solution to dissolve their shells may also have an impact on the eggs’ internal solute concentration.

Works Cited Shanholtzer, S. (2018). Principles of Biology Laboratory Exercises (2nd ed.). Plymouth, MI: Hayden-Mcneil....