Respiration Lab Report

Introduction:

All organisms need to breath. They have pathways that are organic molecules and capture in their ATP. Some of these organisms need oxygen to do this but not all of them require it. Organic carbon molecules are the energy source, and for waste is carbon dioxide (CO2) and water (H2O).
CO2 can combine with water to form carbonic acid during cellular respiration. Phenolphthalein can be used to help detect any changes in pH because of production of CO2 during cellular respiration. Phenolphthalein usually appears clear or colorless in acidic solutions, and red in basic solutions. Procedures:

In the first lab, seven test tubes were attained and six of them were filled with the solutions that were listed (Na Pyruvate, MgSO4, NaF, Glucose, Water, and yeast suspension). The last test tube was filled with water. After they were filled with the solutions they were incubated at 37 degrees Celsius for about forty minutes. After the forty minutes passed take the test tubes and measure the height of the bubbles that formed in millimeters. For the second lab, attain three beakers, and fill them each with 75 mL of the culture solution provided. Obtain the three organisms (fish and elodea) one beaker will be used as a control beaker. Obtain the volume of each organism by filling a graduated cylinder with 25 mL of water and noting if there is an increase in volume above the 25 mL line. Record volumes in table. After placing the organisms in their proper beakers cover each beaker with plastic film or petri dish. Cover the beaker containing the elodea with a coffee can or aluminum. Allow them to respire for about fifteen minutes. After fifteen minutes remove the organisms from the beakers and return them to their original bowls. Add four drops of phenolphthalein to each beaker. Obtain a burette and add NaOH drop by drop. Mix the contents thoroughly. Record amount of NaOh in millimeters on the table. How much phenolphthalein was required to make the solutions turn pink. Do this for all beakers.

Results:

In the first lab we had four of the seven test tubes produce carbon dioxide. Test tubes one, four, and seven did not produce carbon dioxide. Test tubes two, three, five and six produced carbon dioxide.
For lab two, the fish and the elodea produced the same amount of respirations, or respired at the same rate. The amount of NaOH to reach the end point was different, the first beaker was twelve mL above that of the control beaker and the second beaker was four mL below the control beaker.

Organisms Total volume (mL) mL of NaOH Respiration Rate of organism Respiration Rate per mL
Beaker 1: Fish 1 mL 40 mL 8 mL 8 mL
Beaker 2: Elodea 1 mL 28 mL 4 mL 4 mL
Control Beaker 0 32 mL 0 0

Discussion: The biggest source of error in this experiment was contamination in both experiments done. In the first it could have been that the beakers were not properly washed resulting in old solutiongs being left in them and being mixed with the new solutions. This could have caused the CO2 appearing when it should not have showed up or just not showing up at the end. In the second experiment, having the phenolphthalein or the NaOH being contaminated. This could have caused the end point to be more or less than what it should have been. Another source of error could have been not allowing the experiments sit for the allotted time needed for the experiment to be completely finished.
Conclusion:
The purpose of these experiments I believe was accomplished, in the first lab CO2 was produced in most of the test tubes. In the second experiment, the CO2 was produced through respiration from the two specimen. This experiment helps with the everyday life because everybody breathes and produces CO2 and this helps have a clear understanding at the different ways it is produced.