Biosphere 2 Lab Report

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On planet Earth, thousands of different living organisms interact to form an ecosystem where each organism receives its energy from the products of other life forms. Each organism creates something that another organism needs to survive so that the biochemical pathways between organisms is balanced. Without this balance, the entire "chain" could collapse if one link was broken. In 1991, an experiment was created to test and observe the links between organisms and how they interact called Biosphere 2. Soon, I will explain the background/overview of the Biosphere 2 experiment, photosynthesis and cellular respiration, and why Biosphere 2 failed. To begin with, Biosphere 2 was a scientific experiment created to test and observe the …show more content…

In photosynthesis, a plant cell(only plants can use photosynthesis) absorbs light from the sun and uses that light energy in the Electron Transport Chain(ETC) to create molecules of ATP and NADPH(and Oxygen which will leave the cell). These molecules will then be used in a process called the Calvin cycle which will then produce organic compounds. Next, is cellular respiration which uses these organic compounds and Oxygen will be used in a process called glycolysis which creates two ATP. Then, a process called the Krebs cycle uses a molecule called acetyl CoA to produce 4 Co2, 2 ATP, 6 NADH, and 2 FADH2. These products will then be transported to the ETC which will then produce more ATP which will be used as energy and will produce H2O. Overall, the most important thing to know is that the products of photosynthesis, organic compounds and O2, are reactants in cellular respiration which produces the reactants of photosynthesis, Co2 and H2O. Both processes rely on the other, without one, the other will not work which is why Biosphere 2 failed which I will explain …show more content…

During the experiment, their goal was to keep the biosphere in balance which was a difficult task. At almost 18 months in, oxygen was pumped in because the testers inside were running low. They found that they lost approximately 7 tons of oxygen during the experiment. This oxygen loss occurred when carbon in the soil (in the form of compost) broke down and used up O2 and released Co2 into the air which went into the concrete. Without this Co2 available for plants to create O2 with, Oxygen levels decreased from about 21% to 14.2%. Another issue was that balance between organisms was unequal. 25 small vertebrates were used in the project but only 6 survived. This caused a big issue because some of the species were used to pollinate plants, and without this pollination the plants could no longer reproduce naturally. Not only did some species die but some thrived by causing damage to other organisms which cause problems when maintaining food crops because without close inspection, a plant could easily be killed. Although other problems did occur, these were the main reasons why the project failed (esp. the first issue). Although the project was considered a failure, the failure helped the scientists working on the experiment find new

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