Umuc biology lab 3: cell structure and function


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UMUC Biology 102/103
Lab 3: Cell Texture and Function
INSTRUCTIONS:

• On your own and externally coadjutorship, adequate this Lab 3 Tally Sheet electronically and surrender it via the Assignments Folder by the continuance listed in the Plan Schedule (subordinate Syllabus).
• To commence your laboratory exercises, use the Laboratory Manual located subordinate Plan Content. Read the induction and the directions for each exercise/illustration carefully anteriorly completing the exercises/experiments and correspondent the questions.
• Save your Lab 3 Tally Sheet in the subjoined format:  LastName_Lab3 (e.g., Smith_Lab3).
• You should surrender your muniment as a Word (.doc or .docx) or Rich Text Format (.rtf) allay for best compatibility.

Pre-Lab Questions


1. Identify three superior congruousities and distinctions among prokaryotic and eukaryotic cells.

 

2. Where is the DNA sheltered in a prokaryotic cell? Where is it sheltered in a eukaryotic cell?

 

3.  Warrant three textures which stipulate assistance and prophylactic in a eukaryotic cell.

Experiment 1: Cell Texture and Function
The texture of a cell dictates the superiority of its business. You gain end a option of slides that proof rare textures that conduce to tissues business.

Materials:
Onion (allium) Radix Digital Slide Images


Procedure
1. Examine the concord radix tip digital slide pictures on the subjoined pages. Then, corcorrespond to the Post-Lab Questions.
 
Onion Radix Tip: 100X


 
Onion Radix Tip: 1000X

 
Onion Radix Tip: 1000X

 

 
Onion Radix Tip: 100X. Each black foe indicates a opposed core.

 
Onion Radix Tip: 1000X

Post-Lab Questions
1. Mark each of the arrows in the subjoined slide picture: A=Chromosomes, B=Nucleus, C=Cytoplasm, D=Cell Wall
 

2. What is the distinction among the craggy and allay endoplasmic reticulum?

 


3. Would an fleshly cell be efficient to survive externally a mitochondria? Why or why not?

 

 

4. What could you state environing a illustration if you observed a slide picture showing the illustration delay a cell forbearance, but no core or mitochondria?

 


5. Hypothesize why competency of a settle, such as the leaves, are bleak, but other competency, such as the radixs, are not. Use philosophical rationalistic to assistance your theory.


Experiment 2: Osmosis - Direction and Strain Gradients
In this illustration, we gain defy the result of solute strain on osmosis. A semi-permeefficient membrane (dialysis tubing) and sucrose gain form an osmotic environment congruous to that of a cell. This exceptive permeability allows us to investigate the net change-of-place of infiltrate counter the membrane. You gain inaugurate the illustration delay a 30% sucrose breach, and fulfil a set of serial dilutions to form inferior strain breachs. Some of the sucrose strains gain be membrane percolable; occasion others gain not be permeefficient (can you state why this is?).

Materials
(3) 250 mL Beakers
(1) 10 mL Graduated Cylinder
(1) 100 mL Graduated Cylinder
Permanent Marker
*8 Rubber Bands (2 sky cerulean, 2 bleak, 2 red, and 2 yellow)
60 g Sucrose (Sugar) Powder, C12H22O11
4 Consume Beakers (any size)
*Paper Towels
*Scissors 
*Stopwatch
*Water
*(4) 15 cm. Pieces of Dialysis Tubing
*Contains latex. Please use wearing prophylactic gloves if you accept a latex allergy.


*You Must Provide

*Be assured to meaassured and cut solely the protraction you deficiency for this illustration. Reserve the residue for succeeding illustrations.  

Procedure
1. Use the enduring marker to mark the three 250 mL beakers as 1, 2, and 3.
2. Cut immodest strips of dialysis tubing, each 15.0 cm covet. Fill Beaker 3 delay 100 mL of infiltrate and plunge the immodest divisions of dialysis tubing in the infiltrate for at meanest 10 minutes.
3. After 10 minutes, transport one division of tubing from the beaker. Use your thumb and pointer finger to rub the tubing among your fingers; this gain known the tubing. Close one end of the tubing by folding balance 3.0 cm of one end (this gain beseem the profound). Fold it repeatedly and enenduring delay a yellow rubber ligature (use
4. Tie a perplexity in the cherishing dialysis tubing honorable aloft or honorable adown the rubber ligature. This gain form a close and ensures that breach gain not reach out of the tube succeeding in the illustration.
5. To trial that no breach can reach out, add a few drops of infiltrate to the tubing and contemplate for infiltrate reachage. If any infiltrate reachs, redouble the rubber ligature and/or the perplexity in the tubing. Make assured you inculcate the infiltrate out of the tubing anteriorly continuing to the contiguous stride.
6. Repeat Steps 4 - 5 delay the three cherishing dialysis tubes, using each of the three cherishing rubber ligature colors.
7. Reconstitute the sucrose scatter according to the instructions stipulated on the bottle’s mark (your kit contains 60 g of sucrose in a chemical bottle) . This gain form 200 mL of a 30% fund sucrose breach.
8. Use Tefficient 2 to form affixed sucrose breachs that are 30%, 15% and 3% snug, respectively. Use the graduated cylinder and consume beakers to form these breachs. Set these breachs separately.
Tefficient 2: Serial Dilution Instructions
Sucrose Solution mL of Fund Sucrose Breach Needed mL of Infiltrate Needed
30% 10  0
15% 5  5
3% 1  9
3% 1  9
9. Pour 150 mL of the cherishing fund sucrose breach into Beaker 1.
10. Use some of the cherishing fund sucrose breach to form an affixed 200 mL of a 3% sucrose breach into Beaker 2.
Hint: Use your attainments of serial dilutions to form this ultimate, 3% sucrose breach.
11. Meaassured and inculcate 10 mL of the cherishing 30% sucrose breach into the dialysis bag delay the yellow rubber ligature. Close the top of this tubing delay the cherishing yellow rubber ligature.
12. Meaassured and inculcate 10 mL of the 15% sucrose breach in the bag delay the red rubber ligature, and close the top of the dialysis tubing delay the cherishing red rubber ligature. 10 mL of the 3% sucrose breach in the bag delay the sky sky sky cerulean rubber ligature, and close the dialysis tubing delay the cherishing sky sky sky cerulean rubber ligature. The ultimate 10 mL of 3% sucrose breach in the bag delay the breach rubber ligature. Close the dialysis tubing delay the cherishing breach rubber ligature.
13. Verify and archives the primal size of breach from each bag in Tefficient 3.
 
Figure 8: The dialysis bags are filled delay varying strains of sucrose breach and placed in one of two beakers.
14. Place the yellow, red, and sky sky sky cerulean ligatureed tubing in Beaker 2. Place the breach ligatureed tubing in Beaker 1 (Figure 8).
15. Hypothesize whether infiltrate gain career in or out of each dialysis bag. Include your hypotheses, acovet delay assistanceing philosophical rationalistic in the Hypotheses individuality at the end of this progress.
16. Allow the bags to sit for one hour. Occasion waiting, inculcate out the infiltrate in the 250 mL beaker that was used to macerate the dialysis tubing in Stride 1. You gain use the beaker in Stride 19.
17. After allowing the tubing to sit for one hour, transport them from the beakers.
18. Carefully known the tubing. The top of the tubing may deficiency to be cut off/removed as they watch to dry out balance the plan of an hour. Meaassured the breach sizes of each dialysis bag using the 100 mL graduated cylinder. Make assured to leisecure and dry the cylinder adequately among each scantling. 
19. Record your grounds in Tefficient 3.
Tefficient 3: Sucrose Strain vs. Tubing Permeability
Band Color Sucrose % Initial Size (mL) Final Size (mL) Net Displacement (mL)
Yellow       
Red       
Blue       
Green       
Hypothesis:

Post-Lab Questions
1. For each of the tubing divisions, warrant whether the breach after a whilein was hypotonic, hypertonic, or isotonic in correspondentity to the beaker breach in which it was placed.


2. Which tubing increased the most in size? Illustrate why this happened.

 

3. What do the results of this illustration this disclose you environing the not-absolute tonicity among the space of the tubing and the breach in the beaker?
4. What would happen if the tubing delay the yellow ligature was placed in a beaker of distilled infiltrate?

5. How are surplus salts that congregate in cells transferred to the dignity drift so they can be transportd from the whole? Be assured to illustrate how this rule works in stipulations of tonicity.

6. If you wanted infiltrate to career out of a tubing division filled delay a 50% breach, what would the minimum strain of the beaker breach deficiency to be? Illustrate your tally using philosophical proof.

7. How is this illustration congruous to the way a cell membrane works in the whole? How is it opposed? Be inequitable delay your retort.