ByAndy Hubbert 13LD

Caffeine and Adenosine

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

Cocaine Structure

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

Mechanism of action