Question

anaerobic respiration
not all organisms rely on oxygen for cellular respiration. life on earth originally evolved in an environment that lacked oxygen. these organisms instead had to use anaerobic processes to get the energy they needed to survive. the evolution of cyanobacteria and the subsequent increase in atmospheric oxygen was key to the eventual evolution of single - celled organisms and multicellular organisms that used aerobic respiration.
organisms that use anaerobic respiration have an important role in ecosystems. they can live in places where most other organisms cannot, such as the deep sea or areas that are very hot or highly acidic. for example, some microorganisms, such as bifidobacteria, live in the digestive tracts of animals and help in the process of digestion. they must get their atp from anaerobic processes because oxygen is not available.
explain how are the processes of anaerobic and aerobic respiration similar? how are they different?

Explanation:

• Similarity: Both anaerobic and aerobic respiration start with glycolysis, which breaks down glucose into pyruvate and produces a small amount of ATP.
• Difference in oxygen requirement: Aerobic respiration requires oxygen as the final electron acceptor in the electron - transport chain, while anaerobic respiration does not use oxygen.
• Difference in ATP yield: Aerobic respiration produces a large amount of ATP (up to 38 ATP per glucose molecule) through the complete oxidation of glucose in the presence of oxygen. Anaerobic respiration produces much less ATP (e.g., 2 ATP per glucose in lactic acid fermentation or alcohol fermentation).
• Difference in end - products: Aerobic respiration produces carbon dioxide and water as end - products. Anaerobic respiration produces different end - products depending on the type of anaerobic process. For example, lactic acid fermentation produces lactic acid, and alcohol fermentation produces ethanol and carbon dioxide.

Answer:

• Similarity: Both start with glycolysis.
• Difference in oxygen use: Aerobic uses oxygen, anaerobic does not.
• Difference in ATP yield: Aerobic produces more ATP.
• Difference in end - products: Aerobic produces \(CO_2\) and \(H_2O\); anaerobic produces substances like lactic acid or ethanol.