Action Spectrum Apr 2026

A revised action spectrum for vitamin D synthesis by ... - PNAS

An is a graphical representation that plots the effectiveness of different wavelengths of light in driving a specific biological or chemical process. While most commonly associated with photosynthesis, the concept applies to any light-dependent reaction, including human skin responses (sunburn) and vitamin D synthesis. 1. Primary Definition action spectrum

The action spectrum measures the —such as oxygen production or CO2 absorption—against the wavelength of incident light. It identifies which specific "colors" of light are most efficient at fueling a particular reaction. 2. Action Spectrum vs. Absorption Spectrum A revised action spectrum for vitamin D synthesis by