Carbon Dioxide Understanding Essay
Carbon Dioxide Understanding and Production in Elodea, Snail, and Goldfish Introduction
This report discusses an experiment to study the rate of aerobic cellular respiration in aquatic organisms which are Elodea (aquatic plant), Snail, and Goldfish, by measuring carbon dioxide production. Because ectothermic organisms (Elodea, snail, and goldfish) were placed in completely covered beaker, each organism would produce different amount of carbon dioxide. The objective of the experiment is to measure carbon dioxide production in three aquatic organisms, and to determine and compare the rate of cellular respiration in each organism.
Aerobic respiration is the process which body obtains energy by using glucose + oxygen; this reaction takes place in mitochondrion in a cell; And the result of the reaction are carbon dioxide, water, and energy in the form of ATP ( adenosine triphosphate) (Hoefnagels, 2012). According to Biology 6th Edition, plants use light to convert atmospheric carbon (CO2) into carbohydrate (Johnson, 204). So I predicted snail would respire at the fastest rate and produce more CO2 because its weight was heavier than other two organisms.
Labeled 1 through 4, four clean beakers filled with 100 mL of aerated distilled water. Weighted each beaker to the nearest 0.01 g; A goldfish was placed in 100 mL of water in beaker #1, snail and empty snail shell were placed in 100 mL of water in beaker #2, 8 cm Elodea was placed in 100 mL water in beaker #3, in beaker #4 placed nothing. Weighted again each beaker to determine each organism’s weight by subtracting the tare weight from the total weight; completely covered all 4 beakers by aluminum foil to block out all light and waited for an hour. Labeled 4 clean 125 mL flasks 1 through 4. After an hour returned fish and snail to the aquarium, put snail shell and Elodea where found. Used graduated cylinder to measure 25 mL of the water from beaker #1 into flask #1, beaker #2 into flask #2, beaker #3 into flask #3, beaker #4 into flask #4; Didn’t pour out the rest of water in the beakers until collected all data.
Added 4 drops of phenolphthalein into flask #4 swirled and placed it on a white paper (background), added NaOH drop by drop (counted each drop, after each drop swirled the flask) until the solution turns into a faint pink color. Placed flask #1 on a white paper (background), added 4 drops of phenolphthalein and swirled; added NaOH drop by drop (counted each drop, after each drop swirled the flask) until the solution turns into a faint pink color. Added 4 drops of phenolphthalein into flask #2 swirled and placed it on a white paper (background), added NaOH drop by drop (counted each drop, after each drop swirled the flask) until the solution turns into a faint pink color. Placed flask #3 on a white paper (background), added 4 drops of phenolphthalein and swirled; added NaOH drop by drop (counted each drop, after each drop swirled the flask) until the solution turns into a faint pink color.
(A) Tare weight
(B) Weight with organism
Weight of organism
Weight og organism (g)
Rate of respiration (umol CO2/hr/g)*
As shown in table 1: weight with organism – (beaker + water) = weight of organism. Goldfish weight (231.1-227) =4.1g; Snail weight (238 – 232.3 – 0.908 (snail shell weight)) =4.8g; Elodea weight (229.2 – 225.1) =4.1 g. As shown in table 2 in #1 flask (goldfish) added 19 drops/25 mL NaOH which means 76 drops/100 mL, converted into mL by diving 76/20=3.8 mL results goldfish during an hour produced 0.61 rate of carbon dioxide. In #2 (snail) and in #3 (Elodea) flask added exactly the same drops of NaOH which was 12 drops/25 mL, means 48 drops/100 mL. However the rate of respiration came out different: snail -0.21 and Elodea -0.24. (To calculate rate of carbon dioxide production, used the formula form instruction 14 p. Lab 7-3) Conclusion
I was wrong about that snail weight is heavier than other two aquatic organisms and it would produce more CO2, because weight has nothing to do with producing CO2. We weighted each organism in order to compare similar weight organisms because if we compare elephant and mouse clearly elephant would produce more CO2 than mouse. Hypothesis found to be false because snail was dead, that’s why snail didn’t produce CO2. Elodea is a plant therefore it undergoes photosynthesis. The process of photosynthesis utilizes CO2. (C H O + CO O + H O + energy ). Since aerobic respiration produces CO2 as a byproduct, goldfish produced more CO2 than Elodea because they undergo aerobic respiration plus Elodea uses CO2.Next time if I do the experiment again, I would pick live snail so that I can compare goldfish and snail CO2 production.
George, B. J. (2002). Photosynthesis. In Biology (6th ed.). (pp. 183.204). Retrieved from http://highered.mcgraw-hill.com/sites/0073031208/ Hoefnagels, M. (2012). Science, Chemistry, and Cells. In Biology Concepts and Investigation (2nd ed.). (pp. 107). New York: McGraw Hill Compamies, Inc., King, B. et al. (2007). Lab 7: Cellular Respiration. In General Biology: Study Guide and Laboratory Manual (10thed.). (pp. 14). NVCC Alexandria: Pearson Custom Publishing.