Lecture: Unity of Life and Biochemistry

Introduction

• Quote by French biochemist Dr. Jacques Monod: "All that is true for E. coli is true for the elephant."
  • Emphasizes the biochemical similarities among all living things.
  • Importance of shared evolutionary history and identical chemical building blocks in DNA and proteins.

Key Elements in Biochemistry

• Team CHNOPS: Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, Sulfur.
• These elements are essential for life and are involved in biochemical reactions.

The Periodic Table and Elements

• As of 2023, the periodic table lists 118 elements.
• Elements are the simplest form of atoms.

Carbon: The MVP of Life

• Carbon is the most common element in living things.
• Plants and algae use carbon dioxide to make carbon-based molecules.
• Carbon cycles through biogeochemical cycles.
• Carbon can form four covalent bonds, making it versatile in forming organic compounds.

Formation of Organic Molecules

• Organic molecules are composed of carbon and hydrogen.
• Examples: Methane (CH4), Butane (C4H10), and Isobutane are all organic compounds.
• Isomers: Same chemical formula but different atomic arrangements.

Oxygen and Nitrogen

• Oxygen: Forms two covalent bonds (e.g., in CO2).
• Nitrogen: Forms three bonds (e.g., in ammonia).

Biological Molecules

• Four major classes: Lipids, Carbohydrates, Proteins, Nucleic Acids.
  • Lipids: Non-soluble in water, include fats, oils, hormones.
  • Carbohydrates: Sugars and starches, store energy, e.g., glucose.
  • Proteins: Made from amino acids, have structural and functional roles.
  • Nucleic Acids: DNA and RNA, store and transmit genetic information.

Chemical Reactions in Biology

• Hydrolysis: Breaks down molecules by adding water.
  • Example: Digestive process breaking down sucrose into glucose and fructose.
• Dehydration reaction: Forms bonds by removing water.
  • Example: Formation of triglycerides from fatty acids and glycerol.

Conclusion

• The unity of life is seen in the biochemical processes shared across different organisms.
• Upcoming topics: Detailed exploration of water's role in life.