Download To conduct your laboratory exercises, use the

Lab 3: Cell Structure and Function
INSTRUCTIONS:

To conduct your laboratory exercises, use the Laboratory Manual located under
Course Content. Read the introduction and the directions for each
exercise/experiment carefully before completing the exercises/experiments and
answering the questions.
Pre-Lab Questions
1. Identify three major similarities and differences between prokaryotic and eukaryotic
cells.
2. Where is the DNA housed in a prokaryotic cell? Where is it housed in a eukaryotic
cell?
3. Identify three structures which provide support and protection in a eukaryotic cell.
Experiment 1: Cell Structure and Function
Label each of the arrows in the following slide image:
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Post-Lab Questions
1. What is the difference between the rough and smooth endoplasmic reticulum?
2. Would an animal cell be able to survive without mitochondria? Why or why not?
3. What could you determine about a specimen if you observed a slide image showing
the specimen with a cell wall, but no nucleus or mitochondria?
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4. Hypothesize why parts of a plant, such as the leaves, are green, but other parts,
such as the roots, are not. Use scientific reasoning to support your hypothesis.
Experiment 2: Osmosis - Direction and Concentration Gradients
Data Tables and Post-Lab Assessment
Table 3: Sucrose Concentration vs. Tubing Permeability
Table 3: Sucrose Concentration vs. Tubing Permeability
Band
Color
% Sucrose in
Beaker
% Sucrose
in Bag
Initial Volume
(mL)
Final Volume
(mL)
Net Displacement
(mL)
Yellow
Red
Blue
Green
Hypothesis:
Post-Lab Questions
1. For each of the tubing pieces, identify whether the solution inside was hypotonic,
hypertonic, or isotonic in comparison to the beaker solution in which it was placed.
2. Which tubing increased the most in volume? Explain why this happened.
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3. What do the results of this experiment this tell you about the relative tonicity between
the contents of the tubing and the solution in the beaker?
4. What would happen if the tubing with the yellow band was placed in a beaker of
distilled water?
5. How are excess salts that accumulate in cells transferred to the blood stream so they
can be removed from the body? Be sure to explain how this process works in terms
of tonicity.
6. If you wanted water to flow out of a tubing piece filled with a 50% solution, what
would the minimum concentration of the beaker solution need to be? Explain your
answer using scientific evidence.
7. How is this experiment similar to the way a cell membrane works in the body? How is
it different? Be specific with your response.
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