Carbohydrates

Carbohydrates are essential biomolecules composed primarily of carbon (C), hydrogen (H), and oxygen (O). They play crucial roles in energy storage and structural functions in living organisms.

Key Points

  • Etymology:
    • "Carbo" means carbon.
    • "Hydrate" means H₂O.
  • Composition:
    • Contain C, H, O with a general ratio of hydrogen to oxygen of 2:1.
  • General Formula:

Definition

Carbohydrates are polyhydroxy compounds of aldehydes and ketones.


Classification of Carbohydrates

Carbohydrates are classified into three main categories:

Type Definition Example
Monosaccharides Simple sugars that cannot be hydrolyzed into smaller units. Glucose, Fructose, Galactose
Oligosaccharides Carbohydrates that hydrolyze to yield 2-10 monosaccharide units. Sucrose, Maltose, Lactose
Polysaccharides Large carbohydrates that produce many monosaccharides upon hydrolysis. Starch, Cellulose, Glycogen

Monosaccharides

Monosaccharides are the simplest form of carbohydrates. They cannot be hydrolyzed into simpler sugars.

Common Monosaccharides

Monosaccharide Source
Glucose Found in honey and corn
Fructose Found in fruits and vegetables
Galactose Found in milk and dairy products

Oligosaccharides (Disaccharides)

Oligosaccharides are carbohydrates that, upon hydrolysis, yield 2-10 monosaccharide units.

Common Oligosaccharides

Oligosaccharide Formula Source
Sucrose C₁₂H₂₂O₁₁ Found in sugar cane
Maltose C₁₂H₂₂O₁₁ Found in malts
Lactose C₁₂H₂₂O₁₁ Found in milk

Polysaccharides

Polysaccharides are large molecules made up of many monosaccharide units. They are non-sugar carbohydrates.

Common Polysaccharides

Polysaccharide Function Example
Starch Energy storage in plants Potatoes
Cellulose Structural component in plants Cell walls
Glycogen Energy storage in animals Liver

Summary

  • Carbohydrates are essential for energy and structural integrity in organisms.
  • They are categorized into monosaccharides, oligosaccharides, and polysaccharides based on their structure and hydrolysis products.