Final answer:
Fermentation of a glucose molecule yields a net of two ATP molecules. While less efficient than aerobic respiration, which can produce up to 36 ATP per glucose molecule, it allows organisms to generate energy anaerobically.
Step-by-step explanation:
Fermentation of a glucose molecule has the potential to produce a net number of two ATP molecules, two NADH molecules, and two pyruvate molecules.
This process, known as glycolysis, involves the breakdown of one glucose molecule into two three-carbon pyruvate molecules, generating a small amount of ATP without the use of oxygen.
To further clarify, in Stage 1 of glycolysis, two ATP molecules are used, and in Stage 2, four ATP molecules are produced, leading to a net gain of two ATP molecules per glucose molecule under anaerobic conditions.
Different types of fermentation can yield different byproducts, such as lactate or ethanol, depending on the organism. In alcoholic fermentation, commonly used by yeast, glucose is ultimately converted into ethanol and carbon dioxide, also yielding two ATP molecules in the process.
On the other hand, aerobic respiration, which requires oxygen, is far more efficient and can yield up to 36 ATP per glucose molecule.
It is important to note that when oxygen is not present, cells will rely on anaerobic processes, such as fermentation, to produce ATP. Although this process is less efficient than aerobic respiration in terms of ATP yield, it is vital for organisms that can survive in environments lacking oxygen or during times when oxygen is scarce.