Rate Of Oxygen Consumption During Respiration

Submitted By Amanda-Unger
Words: 1292
Pages: 6

Amanda Unger
230113075
Title: The rate of oxygen consumption by germinating peas at varying times during the germination process.
Objective: The objective of this lab was to observe the rate of oxygen consumption of germinating peas at four times in the germinating process, 0 hours, 18 hours, 46 hours and 65 hours, and how the varying times of germination would affect the peas’ oxygen consumption during respiration.
Null Hypothesis: The length at which the peas were left to germinate will not affect the peas’ rate of oxygen consumption during respiration.
Methods: This method was adapted from Blair 2014. This method was used to determine the rate of oxygen consumption of germinating peas during respiration.
A 50mL graduated cylinder was used to measure 20mL of glass beads, dry peas, and germinating peas of 18 hours, 46 hours, and 65 hours, and each was placed into one of 5 test tubes. Once all the beads and peas were placed in test tubes a small amount of cotton was added to the top of each test tube, making sure the cotton did not touch the peas. 1.5g of KOH was weighed and placed in each of the 5 test tubes on top of the cotton and a stopper was placed on the test tube, making sure the cotton with the KOH on it was not touching the stopper. The stopper was then secured onto each test tube with parafilm to ensure no air could neither enter nor escape from the tube.
5 1mL pipettes were prepared by squeezing dye into them, the dye was placed at the 0.1mL measure for the geminating peas. The dry peas and glass beads had their dye placed at 0.9mL. The pipettes were placed horizontally with the measurable side facing up-wards so it was possible to take measurements (Blair, 2014.).
The test tubes were connected via stoppers to the opposite end of each pipette. After each tube was set up, masking tape was used to secure the pipettes in one spot. The system was then left to establish an equilibrium for five minutes. After the five minutes a recording was taken of where the dye laid in the pipettes and this was to be the initial 0 minutes. The system was to be left again for 30 minutes, ensuring the dye didn’t go past the final reading on the pipette, after 22.10 minutes a reading was taken as the dye was approaching the 1mL mark (Blair, 2014.).
After the second reading was taken the experiment was re-set to be done a second time, to ensure accuracy of results. During the second waiting period of 26.52 minutes the rate of reaction was calculated for each test tube using this formula,

After calculating the rate of oxygen consumption of the glass, dry peas, and germinating peas of 18 hours, 45 hours, and 65 hours, all the calculated rates needed to be corrected to take into account environmental factors. To correct each equation the rate of the glass beads was used as an environmental control and was subtracted from the rate of the dry peas, and the peas that had been germinating for 18 hours, 45 hours, and 65 hours (Blair, 2014.).
The corrected values for the dry, 18 hours, 45 hours, and 65 hour peas were then pooled with the class data, after which mean and standard deviation were calculated.
Results: The data obtained from the dye readings and calculations were used to present Figure 1. In Figure 1. The data showed that with each increase in time the peas were left to germinate for, the rate of oxygen consumption increased, from the peas that geminated for 18 hours to the peas that germinated for 65 hours the mean range in their mean oxygen consumption was 0.02099mL/min, which showed an increase in the oxygen consumption by the peas that germinated for 65 hours. In Figure 1. The data showed that the standard deviation of the peas that germinated for 65 hours had a larger standard deviation than the peas that germinated for 0 hours, 18 hours or the peas that germinated 46 hours. The peas that germinated for 65 hours had a standard deviation of 0.00809, while the peas that germinated for 18 hours and 46 hours showed a closer range