Molecules of Life - Lecture Notes

Introduction

• Speaker: Mr. Anderson
• Overview of how food serves as building blocks for life.

Key Points

• Building Blocks of Life:
  • Food is broken down into smaller components (proteins, carbohydrates, fats) that are used to create living organisms.
  • Example: Dave Thomas (founder of Wendy's)
    • His body is composed of components from food:
      • Proteins from burgers → amino acids → body proteins
      • Carbohydrates from buns → sugars → ATP for energy
      • Fats from burgers → lipids in cell membranes.
• Carbon as a Fundamental Element:
  • Life is primarily based on carbon due to its ability to form stable, large molecules.
  • Carbon has four valence electrons, allowing for diverse bonding.
  • Possible alternative life forms could be based on silicon (e.g. Star Trek's Horta).

Functional Groups

• Functional Groups:
  • Groups of atoms that provide specific functions to organic molecules.
  • Important functional groups to memorize:
    • Carboxy Group: COOH, donates H+ to form carboxylic acids.
    • Carbonyl Group: C=O (ketone in the middle, aldehyde at the end).
    • Methyl Group: CH₃, involved in methylation (e.g. DNA).
    • Amino Group: NH₂, necessary for amino acids.
    • Phosphate Group: involved in ATP and DNA formation.
    • Hydroxyl Group: OH, makes molecules polar and soluble.

Polymers and Monomers

• Polymers vs. Monomers:
  • Polymers are large molecules made of repeating units (monomers).
  • Dehydration Reaction:
    • Process of building polymers by removing water.
    • Example: Formation of peptide bonds between amino acids.
  • Hydrolysis:
    • Breaking down polymers by adding water.
    • Example: Breaking proteins into amino acids.

Major Macromolecules of Life

• Nucleic Acids:
  • Two types: DNA and RNA.
  • Made of nucleotides (sugar, phosphate, and base).
  • DNA stores genetic information, RNA assists in its function.
• Proteins:
  • Composed of 20 different amino acids.
  • Structure: Amino group, carboxy group, side chain (R group).
  • Fold into specific three-dimensional shapes (tertiary structure).
• Lipids:
  • Comprised of long hydrocarbon chains (fatty acids).
  • Types:
    • Saturated: no double bonds, solid at room temp (e.g. butter).
    • Unsaturated: at least one double bond, liquid at room temp (e.g. olive oil).
• Carbohydrates:
  • Types:
    • Monosaccharides: Simple sugars (e.g. glucose).
    • Disaccharides: Two sugars (e.g. sucrose).
    • Polysaccharides: Long chains of sugars (e.g. starch).
  • Breakdown through hydrolysis for energy use in cellular respiration.

Conclusion

• Understanding molecules of life helps in grasping how food transforms into essential components of the body.
• The process of digestion and cellular respiration shows the remarkable journey from food to life.