David Goodsell/ProteinDatabase, CC BY-SA
Editor’s notice: Nathan Ahlgren is an assistant professor of biology at Clark College. On this interview, he explains precisely what proteins are, how they’re made, and the wide range of features they carry out within the human physique.
What’s a protein?
A protein is a primary construction that’s present in all of life. It’s a molecule. And the important thing factor a couple of protein is it’s made up of smaller elements, known as amino acids. I like to consider them as a string of various coloured beads. Every bead would characterize an amino acid, that are smaller molecules containing carbon, oxygen, hydrogen and typically sulfur atoms. So a protein primarily is a string that’s made up of those little particular person amino acids. There are 22 totally different amino acids that you could mix in any form of totally different manner.
A protein doesn’t often exist as a string, however truly folds up into a selected form, relying on the order and the way these totally different amino acids work together collectively. That form influences what the protein does in our physique.
The place do the amino acids come from?
The amino acids in our physique come from the meals we eat. We additionally make them in our physique. For instance, different animals make proteins and we eat these. Our our bodies take that chain and break it down into the person amino acids. Then it might probably remake them into any protein that we’d like.
As soon as the proteins are damaged down into amino acids within the digestive system, they’re taken to our cells and form of float round contained in the cell, as these little particular person beads in our analogy. After which contained in the cell, your physique principally connects them collectively to make the proteins that your physique must make.
We are able to make about half of the amino acids we’d like on our personal, however we now have to get the others from our meals.
What do proteins do in our physique?
Scientists should not precisely certain, however most agree that there are round 20,000 totally different proteins in our physique. Some research recommend that there could be much more. They perform quite a lot of features from doing a little metabolic conversions to holding your cells collectively to inflicting your muscular tissues to work.
Their features fall into a number of broad classes. One is structural. Your physique is made up of many alternative sorts of buildings – consider stringlike buildings, globules, anchors, and so forth. They kind the stuff that holds your physique collectively. Collagen is a protein that provides construction to your pores and skin, bones and even tooth. Integrin is a protein that makes versatile linkages between your cells. Your hair and nails are product of a protein known as keratin.
One other massive function that they tackle is biochemistry – how your physique carries out explicit reactions in your cell, like breaking down fats or amino acids. Bear in mind once I stated our physique breaks down the protein from the meals that we eat? Even that perform is carried out by proteins like pepsin. One other instance is hemoglobin – the protein that carries oxygen round in your blood. So that they’re finishing up these particular chemical reactions inside your self.
Proteins also can course of alerts and knowledge, like circadian clock proteins which hold time in our cells, however these are a number of major classes of features that proteins perform within the cell.
Why is protein typically related to muscular tissues and meat?
Various kinds of meals have totally different sorts of protein content material. There are numerous carbohydrates in vegetation like wheat and rice, however they’re much less wealthy in protein content material. However meat generally has extra protein content material. Loads of protein is required to make the muscular tissues in your physique. That’s why protein is commonly related to consuming meat and constructing muscle, however proteins are actually concerned in a lot, rather more than that.
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Nathan Ahlgren receives funding from the Nationwide Science Basis and the Nationwide Institute of Well being.