Polysaccharides

Polysaccharides are long chains of monosaccharide (simple sugar) units linked together by glycosidic bonds. They are complex carbohydrates that serve structural, storage, and functional roles in both plants and animals.

Structure:

• Made up of repeating monosaccharides (e.g., glucose, galactose, mannose).
• Can be:
  • Linear (e.g., cellulose)
  • Branched (e.g., glycogen, amylopectin)
• Classified as:
  • Homopolysaccharides: All repeating units are the same sugar (e.g., starch made of glucose)
  • Heteropolysaccharides: Composed of different sugars (e.g., hyaluronic acid)

Functions:

Examples of Polysaccharides:

Properties:

• Insoluble or poorly soluble in water (especially structural polysaccharides like cellulose).
• Can be digestible (starch, glycogen) or indigestible to humans (cellulose).
• Vary greatly in size, branching, and chemical modifications, contributing to a wide range of functions.

Polysaccharides vs. Other Carbohydrates:

Biological and Industrial Significance:

• Nutrition: Major component of diet (e.g., dietary fiber from cellulose).
• Pharmaceuticals: Used in drug delivery systems (e.g., dextran).
• Biotechnology: Used as gelling agents (e.g., agar, alginate).
• Medical applications: Hyaluronic acid in eye surgery and joint treatments.

Summary Table: