Steroid
A lipid built on a characteristic framework of three six-membered rings fused to one five-membered ring.
Formula / equation
C₁₇ tetracyclic core
Unit
Dimensionless
In depth
Steroids differ only in the functional groups attached to this rigid skeleton, yet those small differences produce dramatically different biological effects. They act mainly as membrane components and as hormones that regulate metabolism and reproduction.
Examples in the real world
Cholesterol regulating membrane fluidity; testosterone and oestradiol; cortisone as an anti-inflammatory.