Lecture on Carbohydrates

Introduction

• Carbohydrates: Chemical compounds consisting of carbon atoms fully hydrated.
• Terminology: 'Carbo' for carbon and 'hydrate' for hydration/water.
• General Formula: ( C_n(H_2O)_n ) (same number of water molecules as carbon atoms).
• Ratio: 1:2:1 of Carbon:Hydrogen:Oxygen._

Types of Carbohydrates

• Monosaccharides: Single carbohydrate molecule (simple sugar).
  • Derived from Greek word for sugar.
  • Example: Glucose, a six-carbon monosaccharide.

Functions of Carbohydrates

• Energy Source: Glucose is the main energy source for metabolism.
  • Important for checking blood glucose levels, especially in diabetes.
• Structural Role: Rigidity in plant cell walls due to polysaccharides like cellulose.
• Genetic Support: Ribose, a five-carbon sugar, supports RNA.

Naming Conventions

Prefix Based on Carbon Count

• Triose: 3 carbons (e.g., Glyceraldehyde).
• Tetrose: 4 carbons.
• Pentose: 5 carbons.
• Hexose: 6 carbons (e.g., Glucose).

Functional Group Prefix

• Aldose: Contains an aldehyde group.
  • Aldohexose: Example - Glucose.
• Ketose: Contains a ketone group.
  • Ketohexose: Example - Fructose.

Stereochemistry

• Fischer Projections: Used to determine the stereochemistry of carbohydrates.
  • Right-side hydroxyl group: R-stereochemistry (D-configuration, "Dexter").
  • Left-side hydroxyl group: L-stereochemistry.
  • Example: Glucose as D-aldohexose, Fructose as D-ketohexose.

Additional Resources

• Fischer Diagram Video: Recommended to understand absolute configuration.
  • Khan Academy video by Jay suggested for further learning.

Conclusion

• Importance of understanding carbohydrates in biological processes.
• Stereochemistry and structure significantly influence the function and biological implications.