While lemons do contain other biomolecules like water, proteins, fats, and minerals, carbohydrates make up the largest proportion of their composition. The carbohydrates in lemons are mainly in the form of:

* Sugars: Fructose, glucose, and sucrose provide sweetness.

* Fiber: Pectin and cellulose contribute to the texture and dietary fiber.

It's important to note that while carbohydrates are the dominant biomolecule, the specific composition of lemons can vary slightly depending on factors like variety, growing conditions, and ripeness.