Research Project 1: The First Big Introduction To Biology Based Experimentation

Introduction: Project 1 was the first big introduction to biology based experimentation for most of us students. It was meant to teach us more about the process of performing biological experiments, as well as, conducting an experiment of our own design. Over the course of project 1 we had to develop skills in making appropriate measurements, proper use of light microscopes, and cell fractionation. All of these skills were applied in our procedures in experiments 1 and 2.

Question & Hypothesis: Experiment 1 consisted of both part 1 and part 2 of Wet Lab 2A. In part 1 of the experiment we had to perform cell fractionations using a specific plant type, which in our case we used cauliflower. While making the cell fractions we used a

In order to determine this we first needed to make the cell fractions by grinding down cauliflower, which broke open the cells and allowed the organelles to float freely. Once we had our cell homogenate we ran it through the centrifuge three times, varying the speed and time it was in there for; this produced the cell fractions pellet 2, pellet 3, and supernatant 3 that were used in part 2. We weren't able to simply put a sample of each under a microscope due to the fact that mitochondria are extremely small organelles, so we had to find a way to test for the presence of mitochondria through the SDH enzyme activity. In part 2 we added DCIP, assay buffer, succinate, and sodium azide to each cell fraction sample, which is the independent variable. DCIP is an artificial electron carrier that changes from blue to colorless when it is reduced; DCIP accepts the electrons from the oxidation of succinate, which occurs in the presence of SDH enzymes. (McAllister pg. 71) Determining the amount of mitochondria in each cell fraction is as easy as looking at the amount of color change, through the change in absorbance at 600 nm, because it’s directly proportional to the amount of mitochondria