El experimento de huevos
Adam Stehley, Caleb Smith, Cameron Long, Jessie Savidge
La senora Reever y el senor Lowas
La 13 de diciembre
La 4 de enero
Title:
Osmosis and Diffusion in Decalcified Eggs
Purpose:
The purpose of this lab was to see how osmosis and diffusion affect eggs that are
submerged in different liquids: water, rubbing alcohol, and corn syrup.
Background:
Diffusion is a process where molecules move from higher concentration to lower
concentrated areas, occasionally through a membrane. Osmosis is a form of diffusion, where it
involves water moving through a selectively permeable membrane. When a cell is exposed to a
hypertonic solution, the water or other materials from inside the cell diffuse out into the solution.
When the cell is exposed to a hypotonic solution, the materials go inside of the cell, and when
the solution is isotonic, materials will not diffuse into or out of the cell. Equilibrium is when
comparing two solutions and the concentration of each solution is equal, this is usually achieved
after diffusion has occurred and the higher concentrated areas balance out with the lower
concentrated areas. An example of diffusion would be the traveling of Lysol or other air-spray
traveling and dispersing across an entire room. An example of osmosis would be an onion being
placed in salt water and most of the water from the cell leaving.
Hypotheses
When the egg is placed into the distilled water, the egg will grow because the solution
will be hypotonic. When it is submerged in corn syrup, it’ll stay the same because the solution
will be isotonic, and in alcohol, it’ll shrink because the solution will be hypertonic.
Materials
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3 eggs decalcified
Marking pen
Weighing dish
String
Calculator
Rubbing alcohol
Distilled water
Gram scale
3 plastic cups
Food coloring
Corn syrup
Ruler
Paper plate
Procedure
First, we laid out 3 paper towels and wrote “1”, “2”, and “3” on them. We placed 1
decalcified egg, after being rinsed and dried, on towel. Then in order to measure the eggs, we
wrapped a string around each egg and measured the string using a ruler to record the length. The
same process was repeated in order to find the width. Next, the eggs were placed each on a gram
scale, measured twice, and the weight was recorded for each egg. We then took 3 plastic cups,
labeled them “1”, “2”, and “3” and placed each corresponding egg into the plastic cups. We
filled cup 1 with distilled water, cup 2 with corn syrup, and cup 3 with rubbing alcohol.
Observations of the substances were then recorded. The height of the solution was then marked
and the cups were set aside for a day. The next day, we recorded observations of the solutions,
and then removed each egg from the cup. The length, width, and weight were all recorded for
each egg using the same process used previously. Then, we used a scalpel and dissected each
egg, recording observations. All materials were then cleaned up and disposed of properly.
Data
DATA TABLE #1 QUANTATIVE DATA
Egg number
Egg 1
Egg 2
Water
Corn syrup
Solution
16 cm
16 cm
Initial Width
16 cm
14 cm
Final Width
0 cm
-2 cm
Change in width
19 cm
19 cm
Initial Length
18 cm
16 cm
Final Length
-1 cm
-3 cm
Change in Length
78.1 g
77.9 g
Initial Weight
82.7 g
52.6 g
Final Weight
4.6 g
-25.3 g
Change in Weight
-32.48%
Percent
Weight 5.89%
Change
DATA CHART #2 – QUALITIVE DATA
Egg number
Egg 1
Egg 2
Blue
Green
Color
Floats
Initial
egg
and Sinks
solution observation
Liquid Level and Stayed same, egg Stayed the same,
increased in size
already equilibrium
explanation
deformed,
Final
egg
and Larger, food coloring Smaller,
food coloring stayed
solution observations spread
suspended
blue cytoplasm, filled Yolk hardened, green
Dissection
with
water,
yolk cytoplasm
observations
firmed
entered
– Corn syrup entered –
Osmosis
and Water
diffusion, water exited
diffusion:
what osmosis
– osmosis
entered the cell,
what exited
Hypertonic
Was the solution Hypotonic
hypotonic,
hypertonic,
or
isotonic
Egg 3
Alcohol
17 cm
15 cm
-2 cm
19 cm
18 cm
-1 cm
88.1 g
72.3 g
-15.8 g
-17.93%
Egg 3
Red
Sinks
Decreased,
egg
absorbed the alcohol
Smaller, food coloring
spread out
Cytoplasm firm, pink,
yolk
firm,
looks
“cooked”
Alcohol entered –
diffusion, water exited
– osmosis
Isotonic
Analysis
The egg placed in distilled water demonstrated the only positive weight change, and the
fact that water was inside of the egg implies that osmosis occurred by having water enter the egg.
The eggs in corn syrup and alcohol both demonstrated negative weight changes, implying that
corn syrup and alcohol have less concentration than the cytoplasm of the eggs.
Conclusion
Our hypotheses were partially correct, because the egg in the water grew due to osmosis,
like we suggested in our hypotheses. Also, the egg in the alcohol lost mass, also matching our
hypotheses. However, the egg in the corn syrup lost a large amount of mass, which does not
match with our hypotheses. In egg #2, the egg in the corn syrup, we expected the solution to be
isotonic, and the egg would retain its shape and size, but the solution was hypertonic, and the
water inside the egg diffused into the corn syrup. According to the data, it shows that water has
simple molecules, corn syrup has larger more complex molecules and alcohol causes problems
within cells.