Which monosaccharide is primarily responsible for the sweet taste in fruit?

Fructose is the monosaccharide primarily responsible for the sweet taste in fruit due to its unique chemical structure, which allows it to bind more effectively to sweetness receptors on the tongue compared to other sugars. It is naturally found in high concentrations in many fruits, giving them their characteristic sweetness.

In contrast, glucose, while still sweet, does not elicit the same level of sweetness as fructose, which can make fruits taste even sweeter. Galactose has a much less sweet profile compared to glucose and fructose and is not typically associated with the sweetness of fruit. Sucrose, although it is sweeter than glucose and galactose, is a disaccharide composed of glucose and fructose, not a monosaccharide, so it is not the correct answer when considering which specific monosaccharide contributes to the sweet taste of fruit.