Egg-Speriment Lab Write Up

Instructions

• Complete the lab write up. Most of the lab is already written for you. Hints and completed information is in black. Instructions for completion are in blue.

Problem & Science Learning TargetCopy the problem and learning target into your

journalProblem: Is sugar able to move freely across the cell membrane?

Science Learning Targets: - investigate the semi-permeable nature of the cell

membrane - Measure the volume of an irregular object using

the displacement method.

Variables identify the variables of this experiment in your journal.

• Independent Variables (variables that we change or manipulate as scientists): Sugar Solution; Pure (distilled) Water

• Dependent Variables (these variables change & depend upon the manipulated variable. They are the data that we gather):

• Controlled Variables (our quality controlled variables that we keep the same):

Egg Observationsrecord qualitative and quantitative observations in your journal

Qualitative ( Description data or qualities)

Quantitative ( numerical data or quantity)

ResearchCopy the research into your journal:- Cell membranes are selectively permeable. This means that they select

(allow) some things to move across the cell membrane but not all things.- Cell membranes allow water to move freely across the cell membrane. - Water moves across cell membranes from high concentration to low

concentration until the concentration on both sides are equal in water concentration. This process is called Osmosis.

- An egg with more water inside the cell membrane will have a larger volume than an egg with low concentration.

- To find the volume of an irregular object, you can use the displacement method. This method involves 3 steps.- Measure a set amount of water in a graduated cylinder. This is your Original

Volume value.- Add your object to the water and measure the new volume. This is your New

Volume value.- Subtract your Original Volume from your New Volume. This value is the

volume of your object.

A MEANINGFUL if-then Hypothesis: give it a try!!

• If (predicted answer to your problem); then (what your data will look like if your prediction is correct).

Hypothesis: choose which official hypothesis fits your first impression and record it in your journal. Also write it on the 5 x 8” index card you were given in class.

If sugar can move freely across the cell membrane, then the volume of the sugar egg will increase. (this is because sugar will move in)

-OR-If sugar can NOT move freely across the cell membrane , then the volume of the sugar egg will decrease. (this is because water will move out since sugar can not move in)

Procedures- write procedures in your journal

• Soak eggs in vinegar for 2 days.• Take initial volume of each egg and record data

and averages• Separate eggs into a distilled water group and a

sugar solution group.• Soak each egg in respective solutions for 2 days.• Take final volume of each egg and record data

and averages

Quantitative Data fill in your data and change the color of your your significant data row, then fill out info for your qualitative data

Eggs in Pure water Lab Table Original

VolumeFinal Volume

1 95 mL 100 mL

2 100 mL 100 mL

3 110 mL 120 mL

4 95 mL 100 mL

5 90 mL 100 mL

6 100 mL 100 mL

Average 98. mL 103. mL

Eggs in Sugar

Quantitative Data

Lab Table Original Volume

Final Volume

1 90 mL 50 mL

2 110 mL 50 mL

3 85 mL 45 mL

4 100 mL 50 mL

5 100 mL 50 mL

6 85 mL 60 mL

Average 95 mL 51 mL

Data create a graph of your averages and put it on the 5 x 8” index card given to you as you entered the room

• Remember TAILS and DRY MIX!

Conclusion InstructionsYour conclusion is an abstract (summary) of your entire project. It should be 6 sentences with the following topics. Use the acronym HADPEN to help you to make a good conclusion paragraph. You should write your conclusion in paragraph form.

• H (hypothesis restated) It was hypothesized that…• A(accepted or rejected) The hypothesis was..• D(data) Summarize significant Data. Identify whether qualitative or

quantitative data was most important in coming to a valid conclusion.• P (Procedures)- critique procedures. Determine whether any improvements

were made and if outside variables were appropriately controlled.• E (explain)- explain why your data supports or rejects your hypothesis. Infer

how the experiment clarifies and supports the scientific principle (science learning target) that the lab was aimed to teach.

• N (new ideas) Comment on new ideas for further experimentation. Ideas can include bringing this experiment to the a higher level, other ways to investigate the same principle, or improvements and expansions on the original experiment.

Conclusion: Write your conclusion in paragraph form on your 5

x 8” index card.

Index Card

• Graph Put on one side of • Conclusion your Index Card

• Your First and Last Name on the Back• Your Class Period