ATP: the energy currency

A day of spending builds sleep pressure. Add caffeine or creatine and see what actually changes.

07:00, awake 0 h
ATP is spent to ADP and AMP, broken down to adenosine which builds sleep pressure on receptors; caffeine blocks receptors, creatine recharges ADP Mitochondria recharge ADP to ATP spend spend ATP charged ADP part-spent AMP spent Phosphocreatine: instant top-up Sleep pressure (adenosine) Adenosine receptors on neurons Tiredness signal quiet adenosine caffeine

Schematic illustration. Sources: Porkka-Heiskanen et al., Science 1997; Fredholm et al., Pharmacol Rev 1999; Kreider et al., JISSN 2017.