BIOLOGY 103 FALL, 2000 LAB 3

Sujatha Sebastian and Caroline Dyar

Bead Size 1st minute 2nd 3rd 4th 5th Average (in um)

2 9 13 19 22 30 5.4

4 4 9 15 19 25 4.5

8 3 7 10 12 14 3.6

Alexis Hilts and Joan Steiner

Lab 3: Beads in Water

1 min 2 min 3 min 4 min 5 min

Small Bead- 5 10 20 28 45

Medium Bead 2 4 5 5 6

Large Bead 1 2 2 3 4

The smallest bead obviously moved much faster than both the medium and the large beads. The medium and the large beads moved about the same distance.

Susy Jones and Katie Gallagher

Bio Lab #3 — Microbead Motion

We had a lot of trouble finding microbeads that were moving, so we only had time to record the movement of the 2um size. We measured the progress in minute intervals: <p>

1 minute: 1 um; <p>

2 mins.: 2um; <p>

3 mins: 6um; <p>

4 mins: 6um; <p>

5 mins: 6um.<p>

This seemed to correspond with some of the results found by our classmates, so if we had been able to find other sizes that were moving, we feel pretty sure our results would follow the averages found.

Katie Kaczmarek and Rachel Hochberg

Lab 3

Experiment 2: molecule movement (Brownian movement) dependent on size

The original hypothesis was that the larger molecules would move slower than the smaller molecules. We tracked the movement of 1 microsphere of each size and found the total range of horizontal movement after five minutes. Our results were:

1 min 2min 3 min 4 min 5min

2um 3ru 3ru 7.5ru 11.5ru 11.5ru

4um 1ru 2ru 2ru 3.5ru 4.5ru

6um 1ru 2ru 2.5ru 3ru 3.5ru

Our data supports the hypothesis that larger molecules have less range of movement, indicating that they move slower than the smaller molecules. The class averages of 5.4um for the 2um microsphere, 4.5um for the 4um microsphere, and 3.6um for the 8um microsphere also support this hypothesis.

Adria Robbin and Elizabeth Paluska

Bead tracking

1min. 2min 3min 4min 5min

2m m 2units 2 2 2 2

4m m 3units 4 4 4 4

8m m 0units 0 0 0 0

Jill McCain and Melissa Donimirski

Lab #3 Results

Size 1min 2min 3min 4min 5min

2 2 2 2 3 3

4 1 2 4 6 7

8 1 3 4 6 8

Jakki Rowlett, Joe Santini, Debbie Plotnick, and Robin Reineke

Lab Report September 27, 2000

1^st Problem: Will the three sizes (2,4,8 cm) polymer cells express movement according to size, Drop of water with polymer was observed at 40X. For the purpose of observing thermal motion.

Hypothesis: The largest size units will move less than the smallest units,

Data:

Smallest 2 cm:

1 min. 4 reticule units

2 min. .5 units

3 min. 0 units

4 min. 0 units

5 min. 4.5 units

Average 6.9 units

Middle size 4 cm

1 min .5 units

2 min. 0 units

3 min. 0 units

4 min. 1 units

5 min. 1.5 units

Average: 3.7

Largest 8cum

1 min. 1 unit

2 min. 0 units

3 min. 0 units

4 min. .5 units

5 min. 1.5 units

Average: 2.71

Conclusion: Our data does support the hypothesis. The largest (8 cm) had the least movement. The middle (4cm) measured in between and the smallest (2 cm) had the greatest range of motion.

2^nd Procedure

First onionskin was prepared on a slide and observed under the microscope at 10X. A drop of sodium chloride was added and the slide then observed. The cell wall was observed to have receded, The plasma membrane has receded from cell wall,

Observation:

Water is leaving the cell wall, Cell is shriveling up. Because some of the water cells are leaving the cell.

Conclusion:

Outside the cell is a greater concentration of salt outside the cell, lots of water inside. Water is leaving cell to try to create a salt balance outside and inside the cell (Concentration gradient). Heat drives the process. Cells create concentration gradients to get even distribution inside and outside of the cell.

Nimia Barrera and Meghan McCabe

Biology Lab #3

Test whether or not smaller sized molecules move slower than larger ones. We are going to test this by observing the distance that different sized microspheres move in five (5) minutes.

We concluded that our data does not prove or disprove our hypothesis, even though the smallest molecules moved the fastest. In order to have proved our hypothesis, the 4 um molecules would have moved further than the 8 um and less than the 2 um.

Jeanne Braha

Lab 3 - Wednesday

9 - 27 - 00

Question: Is there a correlation between the size of a microsphere and the range of its motion? Jeff led a class discussion that led to this conclusion, because the water molecules are all the same size and mass. Thus, it seems logical that the water molecules would be able to make the microspheres move further and/or faster if they had less mass.

I measured the range covered by a microsphere of 2, 4 and 8 microns in a five minute interval to contribute to the class data. The microspheres were suspended in water, and moved by the thermal motion of the water molecules. I put 2 drops of the solution in a depression slide and measured the motion of the microspheres relative to the ocular reticle on the microscope.

My results were as follows:
size: 1 minute 2 minutes 3 minutes 4 minutes 5 minutes

2 3 4 -2 -4 8

4 2 4 5 3 5

8 0 0 1 0 1

(microns) (reticle units)

These results seem to support the hypothesis -- as the size of the microsphere increases, the range of motion decreases. This is an inverse correlation between microsphere size and range of motion. The individual data from the entire class was across the board, but the class data showed weak support for the hypothesis -- 5.6 reticle units; 3.1 and 3.0, respectively.

Allison and Jessica Hayes-Conroy

Lab #3

September 27, 2000

Part 1:

Recorded Data on Microspheres:

Size Coordinates Total Distance Class Average

2um 22, 26, 27.5, 27, 25, 23 5.5 5.6

4um 26, 30, 30, 28, 27, 28 4 3.1

8um 0, 1, 1/4, 1, 1/2, 0 1 3.0

Summary of Procedure and Findings:

Part 2: Observations on the onion molecules’ reaction to water and salt water

Using a microscope, we observed onion cells in water. We saw normal looking live cells with nulcei and cell walls. We then observed the same onion cells in salt water under the microscope. A line began to grow in the middle of many of the cells. The cells were experiencing a net movement of water out of the cell because the concentration of salt was less inside the cell than it was outside.

Srabonti Ali and Jabeen Obaray

Wednesday September 27,2000

The purpose of this lab is to determine whether larger or smaller microspheres move a greater amount of space in a certain amount of time.

Our hypothesis is that the larger microspheres will move a shorter amount of space in a given time than smaller microspheres.

We used our given time to be a total of five minutes, monitoring movement constantly and indicating movement every minute.

Using a 40x lens:

Minute 1 Minute 2 Minute 3 Minute 4 Minute 5

2 micron: 15 21 28 31 37

4 micron: 5 5.5 5.5 7 7

8 micron: 0.5 1 1 1.5 1.5

Initially, for our data on the 2 micron microsphere, it was apparently not moving on its own, but rather by current, so we had to disqualify the data. From our intial results, we would have been able to conclude that the smaller the microsphere, the greater the space it is able to cover in a certain amount of time (in this experiment, a time of five minutes).

However, when we re-collected our data for the 2 micrometer microsphere we found our hypothesis to be false. We found that the 4 micron microsphere moved the greatest amount of space, above both the 2 and 8 micron microspheres.

2 micrometer - 5.5

4 micrometer - 3

8 micrometer - 3

According to group data, there is at least weak support for our hypothesis.

Our individual data differed from group data. This could be due to human error, and due to other variables such as variation is sizes. Trend is more meaningful and accurate in getting representation than singular data.

• Observing onion cells (large in size)
• onion cells in distilled H2O vs. onion cells in sodium chlroide solution
• onion cells in sodium chloride solution - thin line known as plasma membrane moving away from cell wall (in animals plasma membrane is outer most because there is no cell wall). This is because water is moving out of the cell due to the salt solution. This occurs because water concentraiton outside of cell is lower than water concentration inside of cell (because the salt solution had been added), so due to the homeostatic sytem, the water wants to leave the inside of the cell to provide a balance. The driving force behind the concentration gradient is random heat motion. There are more water molecules moving out of than into cell. Cells will create concentration gradients to harness energy and put it into form that can be utilized to drive certain processes. It doesn’t matter what substance you use (ie calcium chloride, sucrose etc.), there will always be concentration gradient.

Leila Ghaznavi and Promise Partner

27 September 2000

Lab 3

Cell Motion

After viewing the movement of dye through water of varied temperatures, we discussed the thermal movement of molecules. Our group hypothesis was "the smaller the molecule, the greater the range of movement." We then observed three sizes of microspheres, 2 micrometers, 4 micrometers, and 8 micrometers, under the microscope and recorded their total range of movement at minute intervals for five minutes.

Our results:

2 um

4 um

8 um

1 min

1

1

1

1

1

1

3

2

1

9

2

1

9

3

1

Our results affirmed the hypothesis. The range of movement for the smallest microsphere was 9x that of the motion for the largest. The middleman lay between the two. Therefore the smaller the molecule the greater its range of motion.

Clare Lindner and Sarah Naimzadeh

Lab #3

Wednesday 27, 2000

Part One

While watching the slide on the television, it seemed as though the smaller the micromolecule, the more area it covered.

So the question we want to answer for this lab is: Do the smaller molecules cover more area than the larger molecules when bombarded with water?

Julie Kwon and Naomi Lim

Wednesday 9/27/00

Lab #3

Introduction:

Does the size of the microspheres affect the distance ranged? Will smaller microspheres move a shorter distance than larger microspheres? Our hypothesis was that the smaller the microspheres, the larger the distance that would be covered in comparison to the larger microspheres, over a period of five minutes

Methods:

First, we placed a couple of drops of microspheres on a slide. We then monitored the movements each minute over a period of five minutes for the 2 micron microspheres, and then for the 4 micron and 8 micron microspheres.

Discussion:

According to our results, the smallest microspheres (2 micron) ranged greater distances than the larger microspheres of 4 and 8 microns. The 4 micron microspheres also ranged greater distances than the 8 micron microspheres. This concurred with the class’ results, as well. Thus, the question arises - What does this random motion have to do with living organisms and cells?

We then observed onion cells with the microscope. The plasma membrane was shrinking away from the cell wall because water is leaving the plasma membrane. How is this related to the experiment we just did? What does this have to do with random motion? When sodium chloride is put into water, the sodium and chloride come apart. There was lots of sodium chloride outside the cell and lots of water inside the cell. Water was leaving the cell in a concentration gradient, to spaces with less water around it.

Before the class actually started the laboratory, we watched the difference between dye placed in cold water and dye placed in warmer water. The dye seemed to have dissolved more quickly in the warmer water. Random heat motion was driving the dye to dissolve more quickly.

Similarly in the onion cell observation, by chance, there will be more water molecules moving out than there will be moving into the cell. It is all random motion. There are fewer water molecules outside than within the cell- an uneven distribution where molecules are free to move across the boundary.

Why does this matter? The cells will create these concentration gradients to harness energy, to transform the energy which the cell can utilize, to carry out metabolic activities. Molecules of the substance will diffuse out until there is an EQUILIBRIUM- even distribution inside and outside the cell. The concentration gradient is a very orderly process- it always moves from more concentrated to less concentrated. What's driving the process is RANDOM- the heat.

The dye will never collect back up to its state when originally dropped into the water because it is an improbable state- an improbable assembly. Moving towards a more probable state.

Our results indicate that the smaller the particle the farther it travels.