College Biology Exam 1 Practice Test

Glucose and fructose are carbohydrates. They are monosaccharides, the simplest sugars built from carbon, hydrogen, and oxygen in a roughly 1:2:1 ratio, and they serve as quick energy sources in cells. Because they can link to form disaccharides like sucrose or polysaccharides like starch and glycogen, this category encompasses both simple sugars and larger carbohydrate polymers. They’re not lipids (fats and oils that are mostly nonpolar), not proteins (made from amino acids), and not nucleic acids (made from nucleotides that store genetic information). The presence of multiple hydroxyl groups and a carbonyl group in these sugars explains their water solubility and their central role in energy metabolism.