BIOLOGY 102: General Biology
Cell Structure and Cell Membranes
Part 1 - Cells [20 points]
Specimen Number | Organism | Eukaryote or Prokaryote | Where Organism is Found | How Organism Obtains Nutrients |
Image 9 | Spirogyra | Eukaryote | Freshwater, free-floating | Autotrophy |
Image 7 | Diatom | Prokaryote | Oceans, freshwater, soils and damp places | Heterotrophy |
Image 6 | Paramecium | Eukaryote | Freshwater, brackish and marine environments, often very abundant in stagnant basins and ponds | Heterotrophy |
Image 2 | Lactobacillus | Prokaryote | Vagina and the gastrointestinal tract | Heterotrophy |
Image 10 | Euglena | Eukaryote | ...view middle of the document...
To begin… 3 minutes later…
Boiling water… In the cup of boiling water, it is my assumption that the molecules within the tea bag are moving faster due to the excessive temperature. Because these molecules are bouncing around so rapidly in such a confined space, they are released from the tea bag into the cup and this is where we notice the water begins to change colors. The molecules are moving rapidly from the tea bag to the water until the molecules are equally distributed within the cup, and that is why we notice that the water stops changing color and our tea is brewed.
Cold water…. In the cold water, on the other hand, the molecules are not moving as rapidly because the temperature is not high enough. Due to the slow motion working of the molecules, it takes longer for them to escape the tea bag and equally distribute themselves within cup as you saw above, after three minutes the color of the water only changed slightly. Ultimately, the temperature affects the rate of diffusion.
Label your 4 plastic cups A, B, C & D
Cut 4 small pieces of paper and using a pencil label them A, B, C & D. These labels will go inside your dialysis tubing.
Prepare your dialysis tubing as follows:
* Soak your dialysis tubing in distilled water until it is flexible
* Take a piece of dialysis tubing and tie a tight knot in one end
* Open the other end of the tubing by rolling it between your thumb and finger
* Fill bag A with 10mL of 1% sucrose solution. Insert label A and squeeze out any air bubbles then tie a tight knot in the end of the tubing to seal it
* Check for leaks, blot dry and set aside
* Fill bag B with 10mL of 1% sucrose solution and complete procedure as before
* Fill bag C with 10mL 25% sucrose solution and complete procedure as before
* Fill bag D with 10mL 50% sucrose solution and complete procedure as before
Make a visual assessment of each bag at time zero, i.e. before placing it into the solution in the cup, and take notes.
Prepare the experimental setup as follows
* Fill cup A with 50% sucrose solution
* Fill cups B, C & D with 1% sucrose solution
* Add bag A to cup A; bag B to cup B and so on
Leave your experiment undisturbed for 60 minutes. Now carefully remove each bag from the cup with its respective solution and blot dry. Measure the volume of liquid inside each bag using your graduated cylinder and record your data in the table below. Be sure to blot dry your graduated cylinder between measurements.
| Beginning volume (milliliters) | End Volume (milliliters) | Difference (milliliters) |
Bag A | 10 | 7 | (-) 3 |
Bag B | 10 | 10.1 | (+) 0.1 |
Bag C | 10 | 12 | (+) 2 |
Bag D | 10 | 14 | (+) 4 |
* When I cut open Bag A, I dropped the bag and water spilled out of bag.
1. Did water move into or out of all of the...