This paper explores fundamental biological and chemical concepts relevant to understanding the impacts of the BP Deepwater Horizon oil spill on marine ecosystems. It covers cellular metabolism and energy transfer, the origins of crude oil in marine environments, the distinction between autotrophic and heterotrophic organisms, and the nitrogen cycle, particularly nitrification processes. The paper culminates in a discussion of bioassay research examining how nitrifying bacteria and archaea responded to crude oil contamination, revealing that the spill disrupted microbial communities that are essential for nutrient cycling in the ocean.
When beginning this assignment, I encountered the word metabolism and realized I had only a superficial understanding of it. In everyday conversation, people frequently use the term—for example, "he is skinny because he has a high metabolism" or "I cannot lose weight because my metabolism has slowed down." These common uses suggest that metabolism is simply something that affects body weight. In reality, an organism's metabolism consists of the chemical reactions that occur within cells. The chemicals involved in these reactions are called metabolites. When these reactions break chemical bonds, a person receives energy. Conversely, when chemical bonds form, energy is released.
There are two main types of metabolic reactions: exergonic and endergonic. Endergonic reactions occur when a person takes in energy because the broken bonds are stronger than the ones being created. Exergonic reactions are the opposite: energy is expelled because the new bonds are greater in strength than the ones that are breaking. Understanding these fundamental processes is essential to comprehending how energy flows through living systems and how disruptions to energy transfer can affect entire ecosystems.
For many years, people assumed that oil came from the remains of dinosaurs that roamed the earth long ago. However, new studies by geologists have contradicted these myths. Current research estimates that over 95 percent of all the world's oil can be traced back to origins in ocean water. These findings indicate that over time, microscopic life—both plants and animals—fell to the ocean floor, creating an abundance of residue that the earth's core heat cooked over millions of years, eventually producing crude oil. David A. Ross, a scientist at Woods Hole Oceanographic Institution, supported this thesis by demonstrating that wherever beds of marine residue are found, crude oil is discovered.
Photosynthesis is one of the most important processes known to humankind. It produces oxygen while eliminating carbon dioxide from the air. That carbon dioxide is one of the factors that creates the energy stored in oils, natural gases, coals, and petroleum—all made possible by the process of photosynthesis. This connection between ancient photosynthetic organisms and modern energy reserves reveals how profoundly life shapes the chemical composition of our planet.
Autotrophs are living organisms that produce food on their own in order to survive. They utilize sunlight through photosynthesis to fabricate their own food and also harness chemical energies through a process known as chemosynthesis. Autotrophs receive their nutrients from carbon dioxide and are often referred to as self-feeders. A heterotroph, by contrast, must depend on other plants and animals for its carbon and other organic substances; it cannot create food on its own.
There are two types of autotrophs: photosynthetic and chemotrophic. Both types produce their own food, but they differ in their energy sources. Photosynthetic autotrophs obtain their nutrients from the sun, while chemotrophic autotrophs thrive in areas where sunlight is unavailable; they get their energy from chemical reactions instead. This distinction is particularly important in understanding how life persists in diverse environments, from sunlit surface waters to the deep ocean floor where no light reaches.
Nitrification is a chemical process in which a nitro group is merged with an organic compound, turning ammonia into nitrite and then converting the nitrite into nitrate. This process can only occur if oxygen is present. Ammonia oxidation is the first step in the nitrification process, during which ammonia is converted to nitrite.
Nitrogen is important to all living beings because it is a major component of amino acids, which in turn make up proteins. Proteins dictate a living entity's enzymes and hormones, which are essential for life. Organic nitrogen also acts as a filter for our bodies when dealing with bodily waste. Photosynthesis and metabolic pathways are similar in that both use light as a mechanism to release and transfer energy throughout biological systems.
In bioassay research related to the BP Deepwater Horizon oil spill, nitrite production was added to studies because the growth of the organisms was taking too long to mature. A bioassay is a method in which scientists use to pinpoint the activity, concentration, and effects of a substance by introducing a living organism to it and gauging the results against their preconceived expectations.
The bioassay was conducted on samples from the BP Deepwater Horizon oil spill to observe the reactions of bacteria and archaea in the oil-filled water and to gain knowledge from their responses. During testing of Nitrosococcus oceani and Nitrosococcus maritimus, the maritimus strain proved more sensitive than its counterpart. In these studies, when nitrite production was removed from the testing, the results showed different outcomes. However, when the production increase was included, it enhanced the growth of the organisms, revealing how crude oil contamination alters the conditions necessary for nitrifying prokaryotes to survive and function.
During this study, we covered many aspects of the disaster to marine life caused by the BP Deepwater Horizon oil spill, but it also showed the good that can come from research opportunities given by the event. From the lessons learned in the bioassay studies, some catastrophes can be a blessing in disguise. Understanding how oil contamination disrupts the microbial communities essential for nutrient cycling provides valuable insights into both environmental damage and ecosystem resilience.
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