Question

What is the difference in structure between oligo- and polysaccharides?

Short answer

The main differences between oligosaccharides and polysaccharides lie in their size, composition, and biological functions. Oligosaccharides are smaller molecules consisting of 2 to 10 monosaccharide units, while polysaccharides are larger, more complex molecules containing more than ten monosaccharide units. Both types of carbohydrates can be linear or branched in structure, and they are formed through glycosidic linkages between monosaccharide units. In terms of biological functions, oligosaccharides contribute to cell recognition, signaling, communication, and digestion, while polysaccharides primarily serve as energy storage and structural components within organisms.

Step-by-step solution

Define oligosaccharides and polysaccharides

Oligosaccharides are carbohydrates that consist of a small number (typically two to ten) of monosaccharide units (sugar molecules) linked together. Examples of oligosaccharides include maltose, lactose, and sucrose. Polysaccharides, on the other hand, are carbohydrates composed of a large number of monosaccharide units (usually more than ten, and often in the 100s or 1000s) linked together. Examples of polysaccharides include starch, glycogen, and cellulose.

Describe the composition of oligosaccharides

An oligosaccharide is formed when two or more monosaccharide units are joined together through a glycosidic linkage. A glycosidic bond is a covalent bond formed between two monosaccharides by a dehydration reaction, which involves the loss of a water molecule. Oligosaccharides can be linear or branched in structure.

Describe the composition of polysaccharides

Polysaccharides are formed by the same type of covalent bonding as oligosaccharides, but with a much larger number of monosaccharide units participating in the reaction. Polysaccharides can also be linear or branched in structure. One key difference between oligosaccharides and polysaccharides is their size and complexity; polysaccharides are much larger and more complex than oligosaccharides.

Compare biological functions of oligosaccharides and polysaccharides

Oligosaccharides and polysaccharides both have important roles in living organisms. Oligosaccharides contribute to the structure and function of cells and tissues and are involved in cell recognition, signaling, and communication. They also play a role in digestive processes, as they can serve as a source of energy when broken down into smaller components. Polysaccharides primarily serve as storage forms of energy (e.g., starch and glycogen) and as structural components (e.g., cellulose in plant cell walls).

Conclusion

In summary, the main difference between oligo- and polysaccharides is the number of monosaccharide units they are composed of. Oligosaccharides are smaller molecules consisting of 2 to 10 monosaccharide units, while polysaccharides are larger, more complex molecules containing more than ten monosaccharide units. Both types of carbohydrates play important roles in biological processes, with oligosaccharides being involved in cell recognition, signaling, and digestion, and polysaccharides serving as energy storage and structural components in organisms.