If two cultures of Escherichia coli were growing in media of the same composition, with one exposed to air and one occurring anaerobically, which would have the larger biomass when growth ceased? Explain your answer.
If two cultures of Escherichia coli were growing in media of the same composition, with one exposed to air and one occurring anaerobically, which would have the larger biomass when growth ceased? Explain your answer.
Answer
The culture of Escherichia coli that is exposed to air would likely have the larger biomass when growth ceases.
Explanation:
Aerobic respiration, which occurs in the presence of oxygen, is much more efficient than anaerobic respiration. During aerobic respiration, E. coli can completely oxidize glucose into carbon dioxide and water, producing a large amount of energy (ATP). This abundant energy allows the bacteria to grow and reproduce more effectively, resulting in a greater accumulation of biomass.
In contrast, under anaerobic conditions, E. coli would rely on fermentation or other anaerobic processes, which produce significantly less ATP per molecule of glucose. With less energy available, the bacteria’s growth rate is slower, and the overall biomass produced is lower compared to aerobic conditions.
Therefore, the culture exposed to air would have a higher biomass due to the efficiency and higher energy yield of aerobic respiration.