Which metabolic product is formed when methanol is metabolized?

When methanol is metabolized in the body, it is first converted to formaldehyde, and then formaldehyde is further metabolized to formic acid. This is significant because formic acid is toxic and responsible for the metabolic acidosis and visual disturbances often associated with methanol poisoning. The metabolic pathway follows this sequence:

1. Methanol → Formaldehyde (catalyzed by the enzyme alcohol dehydrogenase)

2. Formaldehyde → Formic Acid (catalyzed by either aldehyde dehydrogenase or by non-specific oxidation processes)

Formic acid accumulation leads to several detrimental effects, including metabolic acidosis and potential damage to the optic nerve, which can result in blindness. Therefore, the formation of formic acid is a critical aspect of understanding the toxicological effects associated with methanol ingestion.

In contrast, the other choices represent different metabolic products or pathways. Acetic acid, for example, is produced from ethanol metabolism but is not a direct product of methanol metabolism. Acetaldehyde also originates from ethanol metabolism, while hydroxymethylfurfural is a product of sugar degradation and is unrelated to the metabolic pathways of methanol. Thus, the formation of formic acid is the