The Oxford dictionary defines ‘radical’ as “relating to or affecting the fundamental nature of something”. A radical shake up to the parliamentary electoral system or the transformative effect social media has had on society provide some good examples. In chemistry, free radicals do just that in the molecular world; inducing fundamental changes on the nature of another molecule, completely transforming the way it works and how it then interacts with other molecules.  

So how do free radicals cause this big shake up? In society we have what we like to call ‘the loose cannons’ such as the Boris Johnson’s of the world; they need to be well contained or else you never know who they’ll interact with and what they might say or do. In chemistry we have unpaired electrons! Just for a moment, if we flash back to high school chemistry, you may (or may not) remember that molecules are surrounded by rings of electrons that love to go around in pairs. In stable, unreactive molecules, all the electrons are nicely paired up and balanced out. But reactive molecules are known as free radicals because they contain unpaired electron(s) – they are the loose cannons that will readily react with whatever molecule they can to pair up their electrons.

But actions have consequences and one molecule stealing the electrons of another flicks a switch causing changes to the way it behaves; it may even become a free radical itself, and so the domino effect begins. In the molecular world, this domino effect of electron stealing can function as an essential signalling system inside our cells. So free radicals are not all bad, in fact we depend on them! That said, free radicals themselves are completely non-plus about what they react with and will gladly go damage your DNA just to nab that golden electron! So, to ensure free radicals interact with the ‘right’ players and prevent collateral damage our bodies ensure tight border force policing. Just like crowd control, free radicals are tightly compartmentalised and permitted only in safe numbers - not as free as you might expect.