The Essential Role of Lipids in Life

Welcome to Biochemistry Fundamentals, where we make molecular life make sense. Lipids aren’t just

“fats” — they’re molecular multitaskers essential to human life. They make up the

phospholipid bilayer of every cell membrane, creating a selective barrier that keeps the inside of cells

distinct from the outside world. Lipids also serve as long-term energy storage molecules,

packing more than twice the energy per gram as carbohydrates. Beyond that, they act as signaling

molecules — think steroid hormones like estrogen and testosterone — and help the body absorb

fat-soluble vitamins A, D, E, and K.

Even the myelin sheaths insulating your neurons are lipid-rich, allowing fast and