Illustration of a cup of coffee with a stylized skeletal formula (chemical structure) of caffeine superimposed. Caffeine is a central nervous system (CNS) stimulant of the methylxanthine class, present in coffee, tea and many soft and energy drinks. | |
Lizenzart: | Lizenzfrei |
Credit: | Science Photo Library / Garlick, Mark |
Modell-Rechte: | nicht erforderlich |
Eigentums-Rechte: | nicht erforderlich |
Restrictions: | - |