Carbohydrates Overview

Major Types of Macromolecules

• Four main types:
  • Carbohydrates
  • Proteins
  • Fats
  • Nucleic Acids (Nucleotides)

Composition of Carbohydrates

• Composed of:
  • Carbon (C)
  • Hydrogen (H)
  • Oxygen (O)
• General formula: hydrocarbons (C, H connected)

Structure of Carbohydrates

• Types:
  • Monosaccharides: Single sugar (e.g., glucose)
  • Disaccharides: Two sugars (e.g., sucrose)
  • Polysaccharides: Multiple sugars (e.g., starch, glycogen)
• Predominantly exist in a ring shape

Importance of Carbohydrates

• Comprise 1% of human body mass
• Main function: Energy production
• Found on cell membranes, associated with genetic material

Monosaccharides

• Key simple sugars:
  • Glucose
  • Fructose
  • Galactose
• All have the same chemical formula: C6H12O6
• Differences in arrangement make them isomers

Glucose

• Primary monosaccharide for energy production

Fructose and Galactose

• Converted to glucose in the liver

Disaccharides

• Formed through dehydration reactions:
  • Example: Connecting glucose and fructose = Sucrose
  • Process involves removing water (H2O)
• Lactose = glucose + galactose
  • Lactase enzyme needed to break down lactose
  • Lactose intolerance can lead to diarrhea due to osmotic effect

Polysaccharides

• Ingested from plants (starches, cellulose) and animals (glycogen)
• Starch: Branched glucose storage from plants
• Glycogen: Highly branched glucose storage in animals
• Cellulose: Indigestible polysaccharide, provides fiber

Fiber and Digestive Health

• Indigestible polysaccharides bulk up stool and aid in digestion
• Humans lack enzymes to digest cellulose
• Ruminants (e.g., cows) can utilize cellulose for energy due to specific enzymes

Final Notes

• Enzymatic reactions (dehydration and rehydration) are crucial in carbohydrate metabolism
• The structure of carbohydrates (linear vs. branched) affects their digestion and energy storage.