Behind the print: Caffeine molecule
Monday. 7am. Only one thing can get you through the morning.. Caffeine.
You’re not alone; caffeine is used regularly by more than 80% of humans, the most common forms being coffee or tea. Coffee is the second most popular beverage in the world, beaten only by water!
The substance caffeine is actually a psychoactive drug; and the most widely used one in the world, with a total annual consumption of over 120 000 tonnes. The molecule itself is an alkaloid; a nitrogen and carbon-based ring structure (C8H10N4O2), also known as trimethylxanthine. It has a half-life of about 6 hours, and is metabolised by the liver.
Caffeine is consumed worldwide, with the leading coffee drinking country being Finland: an average person gets through 9.6kg per year! Caffeinated drinks go back a long way, to a time before specific effects were known, but today we know that caffeine has both positive and negative effects. Positive effects include alertness, pain relief and increased dopamine production which can increase motivation and productivity. On the other hand, caffeine is addictive and can cause withdrawal symptoms, increases blood pressure and sometimes anxiety, and can lead to insomnia.
The caffeine molecule is absorbed into the blood stream and transported around the body by dissolving in the water that is already present. It is both water and lipid soluble so can cross the blood-brain barrier, and the effects of caffeine come about through a few different mechanisms. Caffeine is chemically similar to adenosine, a neuromodulator produced in the brain that facilitates sleep by inhibiting neuronal functions and dilating the blood vessels in the brain. Due to the similarity, caffeine binds to the adenosine receptors instead, blocking adenosine from acting. Instead of slowing down, the neurons get more active, releasing dopamine and norepinephrine among other things. This creates the alert feeling we get after that shot of espresso. Caffeine is also used by athletes to feel more alert and energetic, and it even has a physiological effect on the muscles. Caffeine increases cAMP – a substance that in this case leads to the release of fatty acids and glycerol to be used as fuel instead of the muscular stores of glycogen. Caffeine is also known to relax smooth muscle, which is why it is often one of the active ingredients in antiasthmatics – it forces the lungs to relax.
This drug that fuels so many of us through Monday morning meetings and late night deadline frenzies is actually a naturally occurring substance produced by about 60 different plants as a pesticide. The most common sources of caffeine include the coffea plants, tea plants, holly yerba mate and Guarana, as well as some citrus trees.
The strategy of these plants in deterring insects and pests backfired somewhat when this defense substance became the most sought-after drug in the world for humans, but its original purpose still stands. Administering caffeine to spiders causes them to spin highly irregular webs, and caffeine is also toxic to a range of insects, as well as cats and dogs. However, the most expensive coffee in the world, known as Kopi Luwak, has actually made its way all the way through an animal before human consumption. The Sumatran wild cat eats coffee berries, and the enzymes in its digestive tract have a desirable effect on the coffee, so it is only harvested from the cat’s faeces!
Caffeine has some cool effects on a few other organisms: it has been shown to increase learning in honeybees, which is adaptive to their foraging strategies. Even more wild is the discovery that a bacterium, Pseudomonas putida, can live off pure caffeine!
If you’re a real caffeine-fiend and feel like you relate to Pseudomonas putida more than the average human being, this caffeine-molecule print is a cool way to express yourself.. and to let people know they shouldn’t talk to you before you’ve had your daily fix!