Background:
In
USA,
an
adult
has
a
daily
intake
of
caffeine
which
is
2.4
mg
kg−1
body
weight.
Caffeine
is
taken
in mostly as coffee and most of the people think that it has a direct or an indirect relationship with their health (Madeira, Boia, Ambrósio, & Santiago, 2017). This is a clear indication that people think that caffeine is affecting their health but they are not sure how. Previous studies have shown that caffeine behaves as a stimulant drug which makes a person very active through a very prominent increase in a person’s productivity, (Yamato et al., 2002). This information will be drawn in from this source to determine the reason for the increment of productivity. It has also been listed that caffeine basically affects the parts of the brain which are responsible for a person’s emotional response (The hippocampus) and these have always been the target organs for researchers (Yamato et al., 2002). This information links neurotransmitters directly to caffeine as hippocampus area is largely governed by the action of neurotransmitters (Tao & Auerbach, 2000).

Keywords: Caffeine; Enzymes; Neurotransmitters; Acetylcholine; Heart rate; Troponin; Adrenaline; Phenylethanolamine N-methyltransferase; Blood pressure.