How Does Cigarette Extract Alter The Rates Of Food Vacuole Formation

Phagocytosis in Tetrahymena
Does Cigarette Extract Alter the Rates of Food Vacuole Formation?
Amber Ellis 11/20/2014
Bio 1130 50
Jennifer Dubberke Abstract

Does Cigarette Extract Alter the Rates of Food Vacuole Formation? The objective of the experiment is to visualize tetrahymena cells and vacuole formation, quantify tetrahymena and vacuole formation over a defined time period. Also, investigate if cigarette extract alters the rate of food vacuole formation. The materials needed in completing the experiment are cover slips and microscope slides, a compound microscope, a timer, a pipette, centrifuge tubes, starved tetrahymena cells, 100 L of tetrahymena cells, 150 L of 1% India Ink, 75 L of tobacco, another 100 L of tetrahymena cells,
100 L of 1% India Ink.
Control Group Begin the experiment by putting 150 L of tetrahymena into a 2ml centrifuge tube.
Make a wet mount of the cells by adding a drop to a microscope slide. Put the slide under the compound microscope lens then observe the behavior of the tetrahymena and vacuole formation. Add an equal volume of 150 L of 1% India ink to the cells. Sample the tubes at 0, 10, 20, and 30 minutes. Count the number of vacuoles in 10 minute increments. Watch for endocytosis (an energy-using process by which cells absorb molecules (such as proteins) by engulfing them) and exocytosis (an energy-using process by which cells discharge molecules). When these steps have been completed, graph the
results. Results showed that as time increased, endocytosis and exocytosis took place. From 0 to 20 minutes, the starved tetrahymena cell engulfed at and increasing rate- endocytosis. Then began to discharge the vacuoles- exocytosis.
Experiment Group
Clean the slides with ethanol, then using 100 L tetrahymena cells and 150 L of 1% India ink on one slide and 150 L tetrahymena cells, 150 L of 1% India ink, and 75 L of tobacco on the other. Repeat the process from the control group in 10 minute increments, observing the vacuole count with a compound microscope. Record results in a table. Results showed that just like in humans, without tobacco breathing performs better and tetrahymena cells are able to consume more vacuoles. With tobacco, breathing is slowed and relatively harder to control. Tobacco affects the cilia which causes the tetrahymena cells to eat less vacuoles.

Introduction The objective of the experiment is to visualize tetrahymena cells and vacuole formation, quantify tetrahymena and vacuole formation over a defined time period. Also, investigate if cigarette extract alters the rate of food vacuole formation. The null hypothesis is tobacco will not affect the amount of ink vacuoles in tetrahymena. The alternative hypothesis is tobacco will affect the ink vacuoles in the tetrahymena. Tetrahymena are small unicellular organisms that can be found in pond water. Tetrahymena are eukaryotes that belong to a group of organisms known as Protista. Phagocytosis is the process by which a cell engulfs a solid particle to form an internal vesicle known as a phagosome.

Materials

In order to satisfy this experiment, a compound microscope is needed, as well as coverslips and microscope slides, a timer, a pipette, and 2ml centrifuge tubes.

Control Group In the control group, 150L of starved tetrahymena cells and 150L of 1% India ink.
Experiment Group In the experiment group, the materials needed are 100 L of tetrahymena cells, 150 L of 1% India ink, 75 L of tobacco, another 100 L of tetrahymena cells, and 100 L of 1% India ink. The controls in this lab is the 1% India ink and tetrahymena cell. Methods For the control group, begin the experiment by putting 150 L of tetrahymena cells into a 2ml centrifuge tube. Release the tetrahymena from the pipette onto the slide, making a wet mount. Insert the slide onto the compound microscope then observe the behavior of the tetrahymena and vacuole formation. When this is done, add an equal amount of 150 L of 1% India ink to the cells. Observe the change in vacuole count for thirty minutes in ten minute increments. Watch for endocytosis (the engulfing of vacuoles) and exocytosis (the discharging of vacuoles). Graph your results in an organized table.

For the experiment group, begin the experiment by getting new slides a coverslips. Using 100 L of tetrahymena cells and 150 L of 1% India ink on the first slide, and 150 L of tetrahymena cells, 150 L of 1% India ink, and 75L of tobacco on the other. Repeat the same process from the control group in ten minute increments for thirty minutes. Observe the difference in vacuole count between with tobacco and without tobacco with the compound microscope. Record the results in an organized table.

Results
Control Group A starved cell was used to produce the results above.
It was observed that as time moved forward, endocytosis and exocytosis took place as the tetrahymena cell ate. From 0 minutes to 20 minutes, tetrahymena engulfed 4 vacuoles. Switching to exocytosis, the tetrahymena discharged a vacuole, leaving the tetrahymena with 3 vacuoles.

Experiment Group Without tobacco, the tetrahymena cells were able to eat more vacuoles. This is due to the cilia being able to perform better without the harsh resistance on the airways. Just like humans, without tobacco, breathing enables you to do more, in this case- eat. With tobacco, the tetrahymena cells ate less vacuoles because the breathing was slowed and much harder to regulate. Just like in humans, tobacco affects the cilia which causes restrictions.

Discussion The data collected supported the alternative hypothesis. Tobacco affected the amount of ink vacuoles in the tetrahymena cell. The tetrahymena cell that did not have any tobacco in it, consumed more ink vacuoles than the tetrahymena cell that had tobacco. Also, a starved tetrahymena cell is more likely to consume more ink vacuoles than a well fed tetrahymena
cell. In comparison to other results, Donna M. Bozzone, conducted a similar experiment, testing a control experiment that demonstrates phagocytosis in the presence of ethanol. Bozzone replaced tobacco with ethanol. Using the same materials and amounts, the tetrahymena cells without ethanol consumed more ink vacuoles than the tetrahymena cell with ethanol. This is due to the loss of microtubule tracks within the cells. Just as with tobacco, tetrahymena cells without tobacco consume more ink vacuoles because of the lack of resistance on airways.
Future Questions
1) Does the duration of starvation on the tetrahymena cells affect the rate of phagocytosis?
2) Will tetrahymena select specific items for ingestion?
3) Does temperature affect the rate of phagocytosis?