3. Mechanism of action
● Acts in the brain
● Acts as an antagonist to adenosine which is a
neurotransmitter in the brain
● Adenosine normally inhibites nerve responses for
example during sleep
● This means it decreases the chances the postsynptic
nerve will fire an action potential
● Caffeine stops this from happening so acts as a
stimulent and increases alertness
5. Mechanism of action
● Binds to the dopamine transport protein
● This prevents dopamine being reabsorbed by the
presynaptic neurone
● This leads to a build up of dopamine in the synaptic
cleft
● This leads to prolonged effects of dopamine as the
postsynaptic neurone is constantly stimulated
● This leads to the high that users get
