Osmosis Egg Lab

Osmosis Egg Lab

By: Cameron, Mia, Maha, Ben

Problem:

How can we observe osmosis across a semi-permeable membrane?

Hypothesis #1

If we add tap water to the egg, then the water will enter the egg causing it to swell up and the mass and circumference will increase

Independent variable:

Substance surrounding the egg

Observations:

Procedure

Control

Control:

Vinegar

Quantitative

Mass: 88.2 grams

Circumference: 15cm

Qualitative

Looks bigger than a normal egg and is more see-through. Feels like a peeled hard boiled egg, and smells like vinegar.

Corn Syrup

Quantitative

Mass: 50.1 grams

Circumference: 10cm

Qualitative

Looks shriveled and see-through, lost the vinegar smell, feels more squeezable and is yellowish

Tap Water

We soaked the egg in vinegar for several days so that it lost its shell. After the shell was gone, we measured the circumference and mass as the controlled group for comparison. We also recorded qualitative data of the egg. Overnight we soaked the egg in corn syrup knowing the egg had a higher concentration of water. The next day we recorded the same data that we did before. Because the egg had a higher concentration of water, all of the water left the egg and it shriveled up, so the mass and circumference decreased. We then filled the beaker with tap water and carefully placed the egg in. We let it sit over night. The next day we examined the egg. It had swelled to almost three times the size it was yesterday. This happened because there was no water in the egg and all of the tap water filled into the egg and caused it to swell up. We recorded the data and it increased greatly.

Quantitative

Mass: 86.9 grams

Circumference: 17cm

Experimental:

Corn syrup and tap water

Qualitative

Bigger than a normal egg and see-through and is squishy Doesnt have a smell

Hypothesis #2

Dependent variable:

Circumference and mass

Background Information

Conclusion

Our hypotheses were right. The first hypothesis was right because the circumference started at 15cm and dropped to 10cm with the corn syrup. Also the mass decreased from 88.2 grams to 50.1 grams. This is because the corn syrup caused the egg to shrivel up. The second hypothesis was corect because the circumference increased from 10cm to 17cm and the mass increased from 50.1 grams to 86.9 grams. This happened because the tap water entered the egg and cause it to swell.

Materials:

There are two different types of transports, Active and passive. Active uses energy and passive does not. Passive transport can occur through diffusion or osmosis. Diffusion is the transport from high to low concentration gradient. Osmosis is the diffusion of water. Facilitated diffusion is another type of passive transport where the carrier proteins shape to allow it to enter or exit the cell. Active transport can be endocytosis or exocytosis or sodium potassium pump. Endo means inside and exo means releases out.

Sources of error

One chicken egg

Vinegar

Corn syrup

Glass beaker

Tap water

Scissors

Yarn

Ruler

Masking tape

electronic balance

One source of error was not being completely accurate wit the circumference on the controlled because Ben didn't want to touch the egg, the measurement could have been a little off. Also we might have not put enough corn syrup in the beaker.

If we add corn syrup to the egg, then the water will move out of the egg causing it to shrivel up and the mass and circumference will decrease