The Molecules of Cells: Structure and Function of Biological Molecules

Introduction

The Importance of Biological Molecules

Biological molecules are essential for the daily functions of living organisms. For example, the enzyme lactase is required to digest dairy products. Individuals who lack this enzyme are lactose intolerant, illustrating the critical role of specific molecules in metabolism and health.

Introduction to Organic Compounds

Life’s Molecular Diversity and the Role of Carbon

Organic chemistry is the study of carbon-containing compounds. The unique properties of carbon allow it to form a wide variety of complex molecules necessary for life.

• Carbon’s Bonding Ability: Carbon can form four covalent bonds, enabling the construction of large and diverse organic molecules.

• Organic Compounds: Molecules containing carbon atoms bonded to other elements, especially hydrogen, oxygen, and nitrogen.

• Carbon Chains: Serve as the backbone for most organic molecules, varying in length and structure (straight, branched, or ring-shaped).

• Isomers: Compounds with the same molecular formula but different structures, resulting in different properties.

• Hydrocarbons: Molecules composed only of carbon and hydrogen; they are hydrophobic and serve as energy sources (e.g., fats).

Example: Methamphetamine exists as two isomers: one is a potent illegal drug, the other is used as a sinus medication. The difference in their effects is due to their structural differences.