Do you just need your daily coffee to function properly? Maybe you should get your sleep instead, because caffeine in the coffee tricks your brain to ‘think’ its’ not tired. This is because caffeine binds to the adenosine receptors in the brain. Normally, the adenosine receptors bind adenosine – and adenosine is a “tiredness”-signal as it builds up during activity and wakefullness. See this animation and learn more.