Why do we eat food?

Each month OUP editor and writer Jonathan Crowe answers your science questions at the monthly SciWhys column. Have a burning question regarding mathematics that you would like answered? Simply email us, and Jonathan will reply what he could. Now: Why can we eat meals?

You might well be thinking the question presented in the name of the site comes with an all-too-obvious response. Most of us understand that we consume food to maintain ourselves alive. But why can we find slaves, ourselves, to our appetites and rumbling stomachs? What’s really occurring inside us who could not occur without another piece of toast, or even an item of fruit, or most vaunted of mid-afternoon pick-me-ups, the sneakily-consumed bar of chocolate?

We are all comfortable with the idea of something requiring gasoline to keep it moving. As a powerhouse necessitates coal or gas to power its own tanks and create energy, thus we are in need of fuel in the kind of meals — to electricity our continuing presence.

The foods we eat supply us with a selection of nutrients: vitamins, minerals, minerals, fat, water, carbs, fiber, protein, and protein. These nutrients have been set to various uses — as construction materials to build the cells and organs where our bodies are created; because of the elements of the molecular machines that keep our tissues functioning as they need to. Each one of these applications is coordinated by a frequent theme: a necessity for electricity to make them occur. And that is where one special sort of nutritional supplement comes on its own. Step forward the carbs.

Carbohydrates are far much better known to us than sugars, but the truth is the candy crystals we all understand since sugar is just a part of the group. Carbohydrates come in very different shapes and sizes. Among the smallest is sugar, which functions as a chemical building block — several copies of sugar can combine together to produce a variety of bigger molecules. By way of instance, starch — located in berries and wheat — would be a carbohydrate generated from several different molecules of sugar combined together in long chains. (According to taste you would not feel that starch has been made from sugar. Though individual molecules of sugar taste sweet to us, even as soon as they’re connected with each other to form starch that the sweetness is missing.)

To fully grasp the way the glucose within our meals may induce the processes happening in our own cells every minute of each day, let us follow a few starches on its travel through the body. A number of the foods we eat are not in a form by which our bodies could do anything helpful. Rather, they will get digested. And so it’s with carbohydrates like starch. This procedure for digestion begins when the food passes our gut; our spit includes particular substances (known as enzymes) that begin attacking the extended chains of carbohydrates, dividing it into smaller fragments.

Digestion proceeds as if our food is consumed and slides into our gut, where an arsenal of additional chemical weapons place to operate on the mouthful we have only swallowed. Provided that what was originally mouth-watering morsels are low to something somewhat less yummy and depart the stomach to go into the long, snaking tube of the gut. By today, the extended chains of starch are broken down into sugar, which can be little enough to maneuver through the liner of our gut and to our blood. Our blood functions as a quick – and – long-distance transportation system, taking the newly-arrived glucose molecules into cells throughout the body.

When sugar develops at its destination and enters the cell, it goes into a compound make-over to convert it to a new compound called pyruvate. And that is where the true fun starts.

Now, allow me to introduce you to some distinctive inhabitant of our own tissues, that your more capsule-shaped mitochondrion (or even mitochondria, in case you are speaking to more than just one). Essentially, mitochondria supply each mobile with its power source. The more energetic a mobile is — so the more energy it requires — the longer mitochondria it comprises. Muscle tissues, which need a great deal of power to power their motion through muscle contraction, can comprise thousands of mitochondria; in comparison, skin tissues, which simply take a small energy source, may comprise just a couple hundred.

But how can mitochondria really power a mobile? Nicely, mitochondria act as factories to get a distinctive compound called ATP. ATP is similar to a mobile mini-battery: it stores electricity and maybe shuttled away to wherein the mobile that electricity is required (at which stage the saved energy could be discharged ).

So what’s the creation of ATP from mitochondria that must perform with us eating carbs? I said before how sugar is converted to pyruvate the moment it enters the cellphone. This pyruvate is then sent into the mitochondrion. Once within the mitochondrion, pyruvate passes a compound manufacturing line, a string of related chemical reactions and molecular procedures which use the pyruvate finally to create ATP. (I will not go into particulars, in spite of the fact that, into some biochemist similar to me, that this course of action is ingenious. Take my word for this if you may.)

This practice of mini-battery generation is dependent upon more than simply glucose to help keep it moving. Additionally, it wants a steady source of oxygen. Really, this dependence upon oxygen will be the entire reason why we will need to breathe every second of our own lives. When we stop breathing, then we stop providing oxygen to the mitochondria in our cells and they cannot create ATP. Without ATP, there’s absolutely not any power to power the procedures necessary to maintain a cell alive. With cells die.

The significance of ATP in our own presence can be emphasized in unexpected ways: Agatha Christie’s Sparkling Cyanide was initially printed in 1945, also features two personalities whose foods in a restaurant were shown to be their final: they’re equally educated with cyanide. Cyanide has its own deadly impact by blocking the compound manufacturing line happening within our mitochondria. If cells can not produce ATP, then they reduce their energy supply and quickly perish (just like at the lack of oxygen). And when this occurs in cells through the entire body concurrently, it is not long until your system as a whole can’t work, since Agatha Christie’s personalities had the misfortune to detect.