Ten o clock, coffee time! we walk to the coffee room, where I meet my colleagues of the laboratory, they are waiting for the coffee machine to serve them a decent cup of freshly brewed CAFFEINE. With sugar, no sugar, milk, no milk. It doesn't matter, it is all about the CAFFEINE.
We have our cups filled and start sipping the hot brew. It is an extraction actually, extremely well performed, as I may say as a chemist: During an extraction you use a solvent to extract molecules from a source. In this case we used hot water, for better solubility and we grinded the coffee beans. Did you ever try to perform a coffee extraction with whole beans? That would not work... The finer the better, the more molecules are extracted.
Ahh, immediately you feel better. Coffee acts fast in the body! Instant succes. And when the Brain is happy, we are happy.
And then a colleague offers me some dark chocolate. Wow, who can say NO to a good piece of chocolate? I definitely can't. It tastes good and we get that happy feeling.
Why is it that coffee works so great in our body?
It is because coffee contains large amounts of caffeine. And caffeine is a very special molecule that regulates lots of mechanisms in our body. It is a xanthine structure with a fused 6 membered and 5 membered ring and nitrogen atoms.
Caffeine
It is an aselective blocker of the adenosine receptors (an antagonist). That is the reason that you sometimes FEEL you heart beating, when you drink too much coffee! It increases the heart rate. (So vice versa, people who suffer from tachycardia (too fast heart rate) get an injection with pure Adenosine (an adenosine receptor agonist) to reduce heart rate.)
Adenosine
In addition, the positive feeling we get from coffee may also be related to its indirect activation of the dopamine receptors! And the increase in dopamine make us feel HAPPY!
How is caffeine converted in our body?
The caffeine molecule is transformed in our body in several active molecules (metabolites) such as paraxanthine, theobromine and theophyline. The last ones are, not coincidentally, compounds that are the active ingredients in CHOCOLATE.
Conclusion
Coffee and chocolate are a good combination in food + on a molecular level they are highly related. And they make an excellent combination on a molecular level :-)
Pictures are handmade using BENZNOTE to make drawing of chemical molecules easy for everybody. Check it out: www.benznote.com