Glucose → ethanol + CO\(_2\) The chemical reaction above represents the process of

The equation shown is:

\[ \text{Glucose} \rightarrow \text{Ethanol} + \text{CO}_2 \]

This is the summary equation for anaerobic respiration in yeast, commonly called fermentation (specifically, alcoholic fermentation). In this process, glucose is partially broken down in the absence of oxygen to produce ethanol (an alcohol) and carbon dioxide.

This reaction is distinct from the other processes listed:

• Oxidation in the biological sense usually refers to the complete breakdown of glucose in the presence of oxygen to yield carbon dioxide and water, releasing far more energy.
• Glycolysis is only the first stage of glucose breakdown, converting glucose into pyruvate. It does not directly produce ethanol. In yeast under anaerobic conditions, the pyruvate from glycolysis is then converted to ethanol and carbon dioxide in a subsequent step, but the overall process is called fermentation, not glycolysis.
• Photosynthesis is the reverse direction: it uses light energy to build glucose from carbon dioxide and water, rather than breaking glucose down.

Alcoholic fermentation is exploited commercially in bread-making (the carbon dioxide causes dough to rise) and in brewing (the ethanol is the desired product).