Friday, December 20, 2013

Cell Communication Lab $

Purpose: The purpose of this experiment was to test the % of cells produced with an a-type, α-type, and a mixed culture. The whole concept of the lab was all about cell communication and for this lab it was the mating of yeast cells. The independent variable was the time intervals, and the dependent variable was the types of cells we measured. These cells include single/double haploid, Shmoos, single/double zygotes, and Asci.

Introduction: As explained in the purpose the concept of the lab is cell communication. So for the yeast there were two mating types a, and α and both of these create signaling molecules that bind to the opposite type of cell. The received signal is converted to a specific mating response which in this lab it is mating and the series of steps is called the signal transduction pathway. The three steps of cell signaling is reception, transduction, and response. Starting out with the first step is reception
Is basically just the detection of the signaling molecules. Once the signaling molecule is detected is binded to a receptor protein. This sets up for the last step which is the cellular response. It could be the arrangement of the cytoskeleton or genes being created in the nucleus. For the yeast the cell response was the production of more cells through mating.

Methods: In the lab we observed α-type and a-type yeast cultures, through a microscope, and how they interacted with each other after 24 hours, 24 hours + 30 minutes, and 48 hours. In a class where teamwork and efficiency is required for success, we devised a system to complete this lab with minimal problems and delays. We had two group members view the cultures that were dropped using a dropper on a slide and then covered with a cover slip. Those two members would relay how many specimen they counted, whether it was the single and budding haplodes, shmoo, single/budding zygotes, and asci, to the third group member who would record the information for later analyses (this lab). The forth group member would take the already observed slides with yeast, bring them to the 50% bleach and 50% water bucket, sanitize the slide and slide cover by soaking them in the bucket, and bring them back to the lab group so they could be used to analyze more yeast cultures. That process was repeated multiple times over multiple days.     

(Data observed from alpha-type yeast, on the left, and a-type yeast, on the right.)
(Time 1 is at 24 hours, Time 2 is 24 hours and 30 minues, and Time 3 is 48 hours.)
Graphs and Charts:

Discussion: The data we collected from our “a” and “alpha” samples showed a slight increase in single haploid and budding haploid populations, respectively. Though this was recorded this could be due to a number of reasons such as quality of sample and area observed under the microscope, as little to no increase should have been recorded. The mixed cultures, being a combination “a” of and “alpha” “marinated” in broth for 24 hours showed significant transitions of the existing single and budding haploid cells in to shmoos, zygotes, and asci. That was due to the ideal environment that they existed in during that time. The “a” type and alpha type yeast cells send out pheromones which are recognized by the opposite type. When they receive these signals, the two cells are induced to mate which results in a fusion of the two cells (which is a zygote). From there, they begin budding and reproducing.

Conclusions: The summary of the whole lab was that with more time the yeast had the more cells produced for the a-type and α-type separately however the mixed culture did not really have a huge difference in cell reproduction from our data. What we have experienced that did not go according to plan was that our initial test for the cultures did not really was seen when put under the microscope. We adjusted every thing on the microscope, but in the end there weren't any results the first day of recording data. So what we did in the end was only have 3 data points for each test on the cultures as shown on the graph.

References: N/A

A picture of a mixed yeast culture, taken through the microscope.
The microscope and the tubes containing the sample we used.

1 comment:

  1. In your discussion, you did not address any of the lab questions for inquiry???