Carbohydrates Overview and Types

Carbohydrates Overview

• Carbohydrates are one of the most common organic molecules.
• They always contain carbon (C), hydrogen (H), and oxygen (O) in a ratio of (CH₂O)ₙ.
• They are the primary energy source in the body.
• Sugars and starches store energy efficiently for use by the body.
• Carbohydrates contain hydroxyl and carbonyl groups.
• Most carbohydrates are polar molecules that dissolve readily in water.
• Carbohydrates are essential for providing energy to various bodily functions.

Types of Carbohydrates

• Monosaccharides: Simple sugars (single molecule).

  • Examples include glucose, fructose, galactose, ribose, and deoxyribose.
  • Glucose is the primary energy source.
  • Glucose, fructose, and galactose are all hexoses (6 carbons)
  • Ribose and deoxyribose are pentoses (5 carbons)
  • Sugars usually end in "-ose".
  • Can exist in straight-chain or ring forms.

• Disaccharides: Double sugars (two monosaccharides bonded together).

  • Examples include maltose, sucrose, and lactose.
  • Formed through a condensation reaction, releasing a water molecule.
  • The bond formed between monosaccharides is called a glycosidic linkage.
  • Bonded together through dehydration synthesis.

• Polysaccharides: Complex carbohydrates (many monosaccharides bonded together).

  • Examples include starch, glycogen, and cellulose.
  • Composed of hundreds to thousands of glucose units.
  • Can be straight chains or branched molecules.
  • Functions include energy storage (starch and glycogen) and structural support (cellulose and chitin).

Digestion of Polysaccharides

• Polysaccharides are large molecules that must be broken down into smaller glucose subunits for absorption.
• Hydrolysis reactions, using specific enzymes, break down complex carbohydrates into simpler sugars.
• Examples of enzymes that break down polysaccharides include amylase.