Lecture Notes on Biological Molecules and Food

Introduction

• Welcome to the kitchen for a lab-style lecture.
• Topics covered:
  1. Three important molecules on Earth
  2. The grossest sandwich ever
  3. An obscure scientist and urine

Biological Molecules

• Essential for survival, energy sources, and instructions for life.
• Types:
  • Carbohydrates
  • Lipids
  • Proteins
  • Nucleic acids (focus on the first three today)

The Scientist: William Prout

• Early 1800s English physician, studied digestion and urine.
• Discovered hydrochloric acid in the stomach.
• Identified chemical composition of urea: CO(NH2)2.
• Categorized foodstuffs into saccharinous (carbohydrates), oleaginous (fats), and albuminous (proteins).

Carbohydrates

• Essential for energy; no one can avoid them.
• Made from sugars (monosaccharides) like glucose and fructose.
• Disaccharides like sucrose are combinations of monosaccharides.
• Polysaccharides are long chains, used for energy storage or structure (e.g., starch, cellulose).

Lipids

• Important biological molecules, insoluble in water.
• Types:
  • Fats (triglycerides): glycerol + fatty acids.
  • Types of fats: Saturated, unsaturated, trans fats, Omega-3 fatty acids.
• Phospholipids make up cell membranes.
• Steroids (like cholesterol) form cell walls and hormones.

Proteins

• Most complex and vital molecules; formed from amino acids.
• Functions: Enzymes, antibodies, endorphins.
• Proteins come from 20 amino acids; 9 are essential and must be ingested.
• Polypeptides form proteins by linking amino acids.

Conclusion

• The lecture concludes the discussion on carbohydrates, lipids, and proteins.
• Encouragement to review content for better understanding.
• Engage with further questions on social media platforms.