Experimental+Design


 * Experimental Design**

-//Problem//: Lab Question: How does glucose affect the cellular respiration of yeast? In other words, our problem was to find and measure the effects of glucose in the cellular respiration of yeast (in aerobic environments).

-//Hypotheses//: Our null hypothesis was that if there is no relation between amount of glucose and rate at which cellular respiration occurs, then there will be no difference in CO2 increase (or water displacement) between yeast with glucose and yeast without glucose. Our alternative hypothesis was that if amount of glucose is related to rate at which cellular respiration occurs, then yeast with more glucose will produce more CO2 (and displace more water) than yeast with less glucose. Our reasoning for this hypothesis was that since glucose is one of the reactants involved in cellular respiration, higher levels of this reactant will be available to be converted into the products of respiration, CO2 and H20. These products will cause more water to be displaced by taking up more space (in the non-computer experiment), and will cause more CO2 to be measured (in the computer experiment).

-//Variables//: The independent variable in our computer experiment was amount of glucose (in grams). The dependent variable was amount of CO2 (in parts per million). In our non-computer experiment, the independent variable was amount of glucose (in grams), and the dependent variable was volume of water displaced (in mL).

-//Control//: Our negative control was yeast without any glucose.

-//Trials//: We performed tests on three different subjects. One of our subjects was the negative control, yeast with no glucose. Our second subject was yeast with 5 grams of glucose. Our third subject was yeast with 10 grams of glucose.