Anaerobic Cellular Respiration: How much ATP is made from each molecule of glucose in anaerobic cellular respiration? Complete the chart below by listing how much ATP is produced from each glucose molecule and at what stage the production of ATP occurs in the anaerobic pathway. In the last column, list other products that are produced at the end of anaerobic cellular respiration. Process Net Yield of ATP At what stage is ATP produced? Is substrate-level phosphorylation involved? Other products produced Anaerobic Cellular Respiration
The Correct Answer and Explanation is:
Here’s the completed chart based on anaerobic cellular respiration:
| Process | Net Yield of ATP | At What Stage Is ATP Produced? | Is Substrate-Level Phosphorylation Involved? | Other Products Produced |
|---|---|---|---|---|
| Anaerobic Cellular Respiration | 2 | Glycolysis | Yes | Lactic acid or ethanol and carbon dioxide |
Anaerobic cellular respiration is a biological process by which cells generate energy without the use of oxygen. This pathway is particularly important in environments where oxygen is scarce or absent, and it enables cells to continue producing ATP, the energy currency of the cell, even under anaerobic conditions. The process begins with glycolysis, a sequence of enzymatic reactions that breaks down one molecule of glucose into two molecules of pyruvate. During glycolysis, a net gain of two ATP molecules is produced through substrate-level phosphorylation. This means that the phosphate group is directly transferred from a substrate to ADP to form ATP, without the involvement of an electron transport chain.
Following glycolysis, the pyruvate undergoes further processing depending on the type of organism and available enzymes. In muscle cells, for example, pyruvate is converted into lactic acid. This process helps regenerate NAD⁺ from NADH, which is essential for glycolysis to continue. In yeast and some bacteria, the pyruvate is instead converted into ethanol and carbon dioxide. These end products are collectively known as fermentation products and are critical for maintaining the redox balance within the cell.
The entire anaerobic pathway is less efficient than aerobic respiration because it yields only two ATP molecules per glucose molecule. However, its simplicity and speed make it a valuable alternative under oxygen-limited conditions. Ultimately, anaerobic cellular respiration ensures survival by sustaining cellular energy levels when oxidative phosphorylation is not an option.
