Molecule of the Day - Adrenaline/Epinephrine
Adrenaline (C9H13NO3), also known as epinephrine, is a naturally-occurring hormone and neurotransmitter found in our body. Along with noradrenaline, it is produced by the adrenal medulla, which is situated above the kidneys.
As a hormone, adrenaline stimulates the sympathetic nervous system, and is partly responsible for the “fight-or-flight” response.
It binds to adrenergic receptors, which are found in almost all tissues, inducing the breakdown of glycogen into glucose (see below), glycolysis, and also inhibits glycogen synthesis as well as insulin secretion. This results in a surge in glucose availability, providing a burst of energy needed to escape any danger.
Adrenaline also promotes vasoconstriction, the narrowing of blood vessels, as well as an increase in heart rate to raise the amount of blood being pumped throughout the body. This causes more oxygenated blood to reach the body at a faster rate, enabling cells to carry out respiration to produce more energy as well.
An interesting study revealed that adrenaline is associated with fear. A 1999 study showed that subjects injected with adrenaline experienced greater feelings of fear upon watching horror films. They also expressed greater negative emotions than the control group.
In nature, adrenaline is biosynthesised from phenylalanine through multiple enzyme-catalysed reactions:
On the other hand, adrenaline can be synthesised from resorcinol and 2-chloroethanoyl chloride in the lab: