Organic Molecules and Their Structure

Introduction

• Organic molecules can be complex, analogous to Christmas trees.
• Analogy: Molecules have a structure (skeleton) and decorations (chemical groups).

Carbon Skeletons

• Basic structure formed using carbon atoms.
• Variability:
  • Length: Chains can vary from 2 carbons (ethane) to more (propane, butane, etc.).
  • Branching: Occurs from 4 carbons onwards (e.g., butane vs. isobutane).
  • Double Bonds: Placement changes the molecule (e.g., 1-butene vs. 2-butene).
  • Rings: Carbon chains can form rings (e.g., cyclohexane and benzene).
• Hydrocarbons:
  • Consist only of carbon and hydrogen.
  • Important for energy storage (e.g., fuels like propane, ethane, butane).

Energy Storage in Fats

• Fats have hydrocarbon components allowing energy storage.
• Structure:
  • Glycerol backbone with fatty acid tails.
  • Stored in adipose tissue for long-term energy reserves.

Isomers

• Definition: Compounds with the same formula but different structures/properties.
• Types:
  1. Structural Isomers: Different covalent arrangements (e.g., butane vs. isobutane).
  2. Cis-Trans Isomers: Geometric isomers with different spatial arrangements around double bonds.
     • Cis: Same side, Trans: Opposite sides.
  3. Enantiomers: Mirror images, similar to right and left hands.
     • Important in pharmaceuticals; one may be active, the other inactive.

Pharmaceutical Examples

• Ibuprofen:
  • Two enantiomers: S-ibuprofen (effective) and R-ibuprofen (less effective).
  • Often sold as a mixture for cost-effectiveness.
• Albuterol:
  • R-albuterol (effective) opens air passages for asthma.
  • S-albuterol can constrict air passages, potentially dangerous.
  • Important to manufacture the correct enantiomer for safety.

Conclusion

• Slight structural differences result in distinct properties and functions.
• Critical understanding of isomers in applications like drug manufacturing.