Carbohydrate Structure and Function

Carbohydrate Structure and Function

• Carbohydrates are polyhydroxy aldehydes or ketones or compounds that yield these upon hydrolysis. Their general formula is C_n(H₂O)_n. For example, glucose has the formula C₆H₁₂O₆.
• Carbohydrates are classified by the number of sugar units:
  • Monosaccharides: single sugar units (e.g., glucose, fructose, galactose). They cannot be further hydrolyzed.
  • Disaccharides: two monosaccharides linked together (e.g., sucrose, lactose).
  • Oligosaccharides: 3-10 linked monosaccharides.
  • Polysaccharides: more than 10 linked monosaccharides (e.g., starch, glycogen, cellulose).
• Monosaccharides are further categorized by functional groups:
  • Aldoses: contain an aldehyde group (-CHO)
  • Ketoses: contain a ketone group (>C=O)
• Monosaccharides are also classified by the number of carbon atoms (e.g., trioses, tetroses, pentoses, hexoses).
• Sugar acids are formed by oxidizing sugars.
  • Mild oxidation produces aldonic acids.
  • Moderate oxidation produces uronic acids.
  • Strong oxidation produces saccaric acids.
• Glycosides are formed when the anomeric carbon of a monosaccharide bonds with a non-carbohydrate component (aglycone).

Types of Carbohydrates

• Homopolysaccharides: contain only one type of monosaccharide unit (e.g., starch, glycogen, cellulose).
• Heteropolysaccharides: contain more than one type of monosaccharide unit.
  • Glycosaminoglycans (GAGs): are heteropolysaccharides including sulfated glycosaminoglycans. Examples include Hyaluronic acid, chondroitin sulfate, dermatan sulfate and keratan sulfate. They are important structural components and lubricants in connective tissues.
• Heteropolysaccharides: Other types include glycolipids and glycoproteins.

Derived Carbohydrates

• Derived carbohydrates are formed from carbohydrates via chemical reactions.
• Sugar alcohols: produced by reducing sugars (e.g., glucose to sorbitol).
• Sugar acids: produced by oxidizing sugars.

Importance of Specific Sugars

• Glucose: A major energy source, important for cellular respiration, nerve function.
• Fructose: A sweet sugar found in fruits, honey. Used to create energy.
• Galactose: Part of lactose, important structural component of glycolipids and glycoproteins. Converted to glucose in the liver.
• Mannose: Found in glycoproteins and glycolipids.

Important Disaccharides

• Sucrose: Table sugar, composed of glucose and fructose.
• Lactose: Milk sugar, composed of glucose and galactose.
• Maltose: A disaccharide formed during starch digestion.

Explore the essential concepts of carbohydrate structure and classification in this quiz. Learn about monosaccharides, disaccharides, oligosaccharides, and polysaccharides, along with their functional groups and significance. Test your knowledge on how carbohydrates play a crucial role in biological systems.