What is the characteristic of monosaccharides?

Monosaccharides are characterized by their simple structure, consisting of single sugar units, and their properties include being soluble in water and having a sweet taste. These sugars, such as glucose and fructose, are the most basic form of carbohydrates and are readily absorbed by the body. Their solubility in water allows them to easily participate in metabolic processes and be transported in the bloodstream, providing quick energy. Their sweetness is a result of their structural configuration, which can interact with taste receptors.

The other characteristics listed in the other options do not accurately describe monosaccharides. For instance, they do not have complex structures, as that would imply a higher degree of polymerization more akin to oligosaccharides or polysaccharides. Monosaccharides are not formed by two sugar units; rather, they are single units that can combine to form larger carbohydrates. Additionally, while monosaccharides can serve as an energy source, they are not used exclusively for energy storage. Rather, they are primarily utilized for immediate energy needs and can be converted into other forms of carbohydrates for storage, such as glycogen or starch, in plants and animals.