Final answer:
Oxygen-dependent organisms harvest energy by oxidizing carbohydrates via cellular respiration to produce ATP, using oxygen from the atmosphere or dissolved in water.
Step-by-step explanation:
Oxygen-dependent organisms, including both autotrophs and heterotrophs, harvest energy through the process of cellular respiration. This process involves the oxidation of carbohydrates in the presence of oxygen, which results in the production of ATP (adenosine triphosphate), the cell’s energy currency. The reaction of glucose with oxygen produces carbon dioxide and water, with the release of energy stored in the chemical bonds of glucose. This energy is then used to synthesize ATP from ADP and inorganic phosphate.
Organisms acquire oxygen from their environment. Terrestrial organisms can breathe oxygen directly from the atmosphere, while aquatic organisms obtain dissolved oxygen from water. The availability of oxygen can vary depending on factors such as temperature, biological activity, and the rate of oxygen delivery to the system.
It’s important to note that while all animals require oxygen, not all bacteria do. Plants, in contrast, are the primary producers that use the energy in sunlight to create energy-rich organic molecules through photosynthesis. These organic molecules serve as the “food” that sustains other organisms within the food web.