Cell biology and proposed mechanisms
ATP (adenosine triphosphate)
ATP is the molecule cells use to move energy from where it is released to where it is spent. Breaking one of its phosphate bonds releases usable energy; the cell then rebuilds it. It is not stored in bulk — an adult recycles a mass of ATP comparable to their own body weight each day.
Also called ATP, adenosine triphosphate
What it is
Adenosine triphosphate is a nucleotide with three phosphate groups in a row. Splitting off the outermost phosphate releases energy that drives muscle contraction, ion pumping, protein synthesis and almost everything else a cell does. The product, ADP, is recycled back to ATP, mostly by oxidative phosphorylation in the mitochondria.
The useful thing to know is that ATP is a turnover currency rather than a fuel tank. The body holds only a few grams at any moment and remakes it continuously. “Boosting ATP” therefore means raising the rate of production, and only for as long as the stimulus lasts.
Where it comes up
ATP is the central idea in photobiomodulation. A 2016 review in the IEEE Journal of Selected Topics in Quantum Electronics states the leading hypothesis: red and near-infrared photons are absorbed by cytochrome c oxidase, displace inhibitory nitric oxide from the enzyme, and increase electron transport, mitochondrial membrane potential and ATP production.
How it is measured
In cells and tissue samples, in a laboratory.
Why it matters here
ATP is where almost every red light explanation ends up. Worth knowing: it is a currency the body remakes continuously rather than a tank that fills, so a rise means a faster rate while the stimulus lasts.