Biochemistry Fundamentals

Biochemistry studies the chemical processes that occur in living organisms. Everything that happens in your body — breathing, thinking, moving — involves chemical reactions. The four major classes of biological macromolecules are: carbohydrates (energy), lipids (membranes, hormones), proteins (enzymes, structure), and nucleic acids (DNA, RNA — genetic information).

Enzymes are protein catalysts that speed up chemical reactions without being consumed. They work by lowering the activation energy needed for a reaction. Each enzyme has an active site — a specific pocket that fits its substrate (the molecule it acts on) like a lock and key. Temperature, pH, and inhibitors can affect enzyme function — critical knowledge for understanding metabolism and drug action.