If you could see every chemical reaction that happens in your body on a daily basis, you would be astounded. These reactions underpin everything we do from the food we eat to the world around us. Let us walk you through your daily life, exposing the science that you probably take for granted.
The first part of your day is spent waking up and overcoming your grogginess from the rest you have had that night (called sleep inertia). A complex range of neurotransmitters and hormonal balances are involved in the cycles that regulate your sleep and waking up.
Your body has a circadian rhythm which helps manage the alertness of your body during the day and keeps you sleepy at night. A couple of hours before you are due to wake up, it activates the physiological processes needed to get you out of bed. For example, it relays a message to your body to stop producing the hormone melatonin, which encourages sleep.
The next item on your morning agenda might be to cook breakfast as you start to feel hungry. When you haven’t eaten in a while and your stomach starts to complain, scientists say you feel ‘homeostatic hunger’ because your energy stores are running low. A hormone called ghrelin starts to rise until you start to eat.
If you feel the urge for a full English fry-up, then a whole explosion of chemical reactions are needed to get a plate together. Fry bacon at a sizzling high heat and you are using the Maillard reaction to your advantage. This is a chemical reaction between amino acids and sugar in the food that give it a brown colour and the delicious taste of foods including meat, bread, chocolate and roasted coffee.
You probably stop thinking about your food as soon as it is eaten, but this is where the science starts to heat up. Digestion is an impressive process that converts your food to fuel. Our bodies are a digestion machine, with our teeth, tongue, saliva, liver, pancreas, digestive tract and stomach all playing a role. Enzymes such as pepsin and lipase tackle the component parts of our food like proteins and fats. We even have hydrochloric acid in our stomach to annihilate bad bacteria.
Throughout the rest of your day, the exercise you hopefully get time for will also give your body a chemical workout. Your body needs extra oxygen so your breathing increases and more blood gets pumped to your muscles. Lactic acid forms if you don’t get enough oxygen, explaining the puffed out feeling you get if you are asthmatic. This lactic acid gives you that familiar burning sensation and forces you to take some rest to recover.
How will you spend your evening? Whatever you do, there are likely to be biological and chemical reactions firing off all over the place. If you are spending time with a romantic partner, then science actually plays more of a role than you think.
A team of scientists led by Dr Helen Fisher at Rutgers University has theorised that romantic attachment is based on three sets of hormonal groups. Lust is triggered by testosterone and estrogen, attraction by dopamine, norepinephrine and serotonin, and attachment by oxytocin and vasopressin. If you choose to spend time with friends instead, many of these chemical cocktails also play a role. A shot of dopamine is that rewarding warm feeling you get when you do something pleasurable.
It has been a long day, but your body is a constant battleground of chemical and biological reactions that trigger the millions of functions of your body. Your body starts to get ready for sleep. We still don’t fully understand the science of everything, including our mysterious dreams. However, chemical reactions underlie everything you do, which is both terrifying and comforting at the same time.