Cell Structure Function | what is cell function | cell structure function

INSTRUCTIONS: Cell Structure Function

·    Cell Structure Function own and without assistance, complete this Lab 3Answer Sheet electronically and submit it via the Cell Structure Function | what is cell function | cell structure functionAssignments Folder by the date listed intheCourse Schedule (under Syllabus).

·         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.
·         Save your Lab 3Answer Sheet in the following format:  LastName_Lab3 (e.g., Smith_Lab3).
·         You should submit your document as a Word (.doc or .docx) or Rich Text Format (.rtf) file for best compatibility.

Pre-Lab Questions

  1. Identify the major similarities and differences between prokaryotic and eukaryotic cells.

 

  1. Where is the DNA housed in a prokaryotic cell? Where is it housed in a eukaryotic cell?
  2. Identify three structures which provide support and protection in a eukaryotic cell.

Experiment 1: Cell Structure and Function

Post-Lab Questions

  1. Label each of the arrows in the following slide image:
  1. What is the difference between the rough and smooth endoplasmic reticulum?
  2. Would an animal cell be able to survive without a 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?
  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

Band ColorSucrose %Initial Volume (mL)Final Volume (mL)Net Displacement (mL)
Yellow    
Red    
Blue    
Green    

Hypothesis:

Take a picture of your results. Include a note with your name and date on an index card in the picture. Insert picture here:

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.
  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.
  1. 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.
  2. How is this experiment similar to the way a cell membrane works in the body? How is it different? Be specific with your response.

LAB TESTS INSTRUCTIONS

Label 3 beakers  (1, 2 and 3) but start with beaker 3

  1. Fill Beaker 3 with                                    100 ml of

water

Submerge dialysis tubing

for at least 10 min

                                                   Beaker 3  

 Reconstitute the sucrose packet according to the instructions on the label.

  1. You will end up with 200 ml of a 30% solution of sucrose.
  2. Use table 2 and what you know about dilutions to make the different concentrations of sucrose. Ask if you have questions.

Cell Structure Function | what is cell function | cell structure function

I use the following equation to make dilutions but you can do it differently as long as you understand what you are doing.

C1V1 = C2V2 

C1 is the initial concentration
V1 is the initial volume

C2 is the initial concentration

V2 is the initial volume

So, for example, if you want to make 30 ml (V2) of a 3% solution (C2) from a 30% solution (C1), you would set up the equation, the following way.

C1V1 = C2V2

(30)(V1) = 3%  30

 V1 would equal 3.  So, take 3 ml of the 30% solution and mix it will 27 ml of water (30 – 3).

Beaker 1         – Put 150 ml of the 30% solution directly into the beaker

Put 10 of the 3% solution into the green bag (you will need to read the directions to learn how to do this).                                      Seal this bag and put it into beaker 1

Questions:  In the question section, it will ask you if this is an isotonic, hypertonic or hypotonic solution.

What you have is a 3% solution in the bag in a 30% solution in the beaker?

The question is asking what is the tonicity of the solution in the bag compared to the beaker?

Beaker 2 –Take your remaining 30% sucrose solution.  You must now make 3% sucrose solution from the 30%.

Put the 3% solution into beaker 2.

You will then make the red bag with a 15% solution, the blue bag with a 3% solution and the yellow bag with a 30% solution.  Read the directions for more details.

Questions:  In the question section, it will ask you if this is an isotonic, hypertonic or hypotonic solution.

For the red bag, you have a 15% solution in the bag in a 3% solution in the beaker.

For the blue bag, you have a 3% solution in the bag in a 3% solution in the beaker.

For the yellow bag, you have a 30% solution in the bag in a 3% solution in the beaker.

The question is asking what is the tonicity of the solution in the bag compared to the beaker?

Record the initial volumes in table 3.

The beakers must then sit for 1 hour.

After 1 hour, open the bags and pour the contents into a graduate cylinder.  Record this volume as the final volume.