Osmosis & Diffusion Lab

Procedure 1: Surface Area and Cell Size

• Cell size and shape are important factors in determining the rate of diffusion.

– Think about cells with specialized functions, such as the epithelial cells that line the small intestine or plant root hairs.

– What is the shape of these cells?

– What size are the cells?

– How do small intestinal epithelial and root hair cells function in nutrient procurement?

What size are the cells?

• http://learn.genetics.utah.edu/content/cells/scale/

What is the shape of these cells?

How do small intestinal epithelial and root hair cells function in nutrient procurement?

What is the purpose of this activity?

What will this look like in my lab notebook?

• Date: The date the entry was made • Title: The title says what you did. It should be brief (aim for ten words or less) and

describe the main point of the experiment or investigation. An example of a title would be: "Effects of Ultraviolet Light on Borax Crystal Growth Rate". If you can, begin your title using a keyword rather than an article like 'The' or 'A'.

• Purpose: The question or hypothesis you are investigating. In other words, why are you doing the investigation? The goal of the experiment.

• Background (if needed): Give context for the activity and summarize any research you did before the activity. Be sure to cite any resources used. This may include references to published literature or scientific talks, a short synopsis of your thought process, and references to previous experiments in the lab.

• Procedure: Describe the steps you plan to complete during your investigation. Be sufficiently detailed that anyone could read this section and duplicate your experiment, but keep it succinct. Abbreviations and fragment sentences are fine. Write it as if you were giving direction for someone else to do the lab. It may be helpful to provide a figure to diagram your experimental setup.

Observations: All that happened (planned or unplanned)

• Raw Experimental Data: Record all results from your investigation. Also, write the names of all lab

partners. Numerical data is usually presented as a table and needs a label, number, and units. If using a table, each column should be headed with a label and units. Observations should be sufficiently detailed for someone else to understand. Data represents the facts, not an interpretation of what they mean. If you needed to change your procedure, you may record the changes here.

• Data Analysis (if needed): Processing of raw quantitative data, graphs and interpretations. Show sufficient work so that an educated reader can follow what you did. Include units and correct significant figures (sig figs). Include any figures or graphs that will help with the analysis of your data. Graphs and figures must both be labeled with a descriptive title. Label the axes on a graph, being sure to include units of measurement. The independent variable is on the X-axis. The dependent variable (the one you are measuring) is on the Y-axis.

• Conclusion/Ideas for Future Experiments: Summarize the lab. Go back to your purpose and answer the question or address your hypothesis (accepted or rejected and why). Use data and analysis to support your answer. When you refer to figures and graphs, the first figure is Figure 1, the second figure is Figure 2, etc. If your results were unexpected, explain why and make a conjecture if possible. If you were to do this investigation again, how might you have done it differently?

Many of these item can be very brief.

What will this look like in my lab notebook?

• Date: The date the entry was made • Title: The title says what you did. It should be brief (aim for ten words or less) and

describe the main point of the experiment or investigation. An example of a title would be: "Effects of Ultraviolet Light on Borax Crystal Growth Rate". If you can, begin your title using a keyword rather than an article like 'The' or 'A'.

• Purpose: The question or hypothesis you are investigating. In other words, why are you doing the investigation? The goal of the experiment.

• Background (if needed): Give context for the activity and summarize any research you did before the activity. Be sure to cite any resources used. This may include references to published literature or scientific talks, a short synopsis of your thought process, and references to previous experiments in the lab.

• Procedure: Describe the steps you plan to complete during your investigation. Be sufficiently detailed that anyone could read this section and duplicate your experiment, but keep it succinct. Abbreviations and fragment sentences are fine. Write it as if you were giving direction for someone else to do the lab. It may be helpful to provide a figure to diagram your experimental setup.

Observations: All that happened (planned or unplanned)

• Raw Experimental Data: Record all results from your investigation. Also, write the names of all lab

partners. Numerical data is usually presented as a table and needs a label, number, and units. If using a table, each column should be headed with a label and units. Observations should be sufficiently detailed for someone else to understand. Data represents the facts, not an interpretation of what they mean. If you needed to change your procedure, you may record the changes here.

• Data Analysis (if needed): Processing of raw quantitative data, graphs and interpretations. Show sufficient work so that an educated reader can follow what you did. Include units and correct significant figures (sig figs). Include any figures or graphs that will help with the analysis of your data. Graphs and figures must both be labeled with a descriptive title. Label the axes on a graph, being sure to include units of measurement. The independent variable is on the X-axis. The dependent variable (the one you are measuring) is on the Y-axis.

• Conclusion/Ideas for Future Experiments: Summarize the lab. Go back to your purpose and answer the question or address your hypothesis (accepted or rejected and why). Use data and analysis to support your answer. When you refer to figures and graphs, the first figure is Figure 1, the second figure is Figure 2, etc. If your results were unexpected, explain why and make a conjecture if possible. If you were to do this investigation again, how might you have done it differently?

• You will be paired by sticks. You will have the rest of today to complete this lab.

• Analysis and conclusion will be completed as homework.