There are 118 elements on the intervalic desk, and also you would possibly suppose we are made up of a lot of them. However that is not the case; the advanced techniques that make up our our bodies have a surprisingly easy elemental make-up.
“Of 118 elements, the last thing I read was that 97% of our body’s weight is just four elements,” Steven Townsend, an natural chemist at Vanderbilt College, informed Reside Science. These 4 elements are oxygen, carbon, hydrogen and nitrogen. So what, precisely, do these elements do?
Oxygen definitively holds first place, making up 65% to 67% of the human physique by weight, Townsend stated. That is as a result of our our bodies are largely water — round 50% to 60% — so most of the oxygen is the “O” in H2O. Oxygen can be essential for vitality manufacturing and metabolism, or the chemical processes that happen inside the physique, in line with a 2016 evaluation in the journal Nature Critiques Most cancers.
Subsequent up is carbon, which makes up round 18% to 19% of the physique by weight, Townsend stated, which is not stunning contemplating carbon is a significant element of most life on Earth. Carbon makes up the spine of fat, carbohydrates and proteins, so this component is a significant constructing block of the physique and the meals we use to gasoline it.
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Coming in at No. 3 is hydrogen. There are extra hydrogen atoms in the human physique than another component, nevertheless it makes up simply 9% to 10% of our our bodies by mass. Hydrogen is the different component in H2O, and there are two hydrogen atoms for each oxygen atom. Plus, hydrogen is a key element of proteins, carbohydrates and fat. However despite the fact that hydrogen holds the majority in variety of atoms, it is considerably out-massed: Oxygen and carbon have atomic weights that are almost 16 and 12 occasions that of hydrogen, respectively. In different phrases, it takes 16 hydrogen atoms to match the mass of 1 oxygen atom, in order that’s why hydrogen makes up solely one-tenth of our mass.
Quantity 4, at round 3%, is the most plentiful fuel in Earth’s environment: nitrogen, in line with Townsend. Nitrogen is essential to proteins and their constructing blocks, known as amino acids. Nitrogen can be a significant element of DNA and RNA, together with of their nitrogenous bases. Each have cytosine, adenine and guanine; DNA has thymine, and RNA sports activities uracil. In different phrases, with out nitrogen, the cells in your physique could not retailer genetic info or replicate. A bonus component, the fifth most common in the human physique, is calcium, which makes up 1% to 2% of people by mass. Greater than 99% of that calcium is discovered in the bones and tooth, in line with the Nationwide Institutes of Well being.
Nonetheless, elements aside from these high 5 matter, too Townsend stated. Take sodium, as an illustration. It makes up solely 0.2% of the physique, however “it’s a super important mineral — it helps balance the fluids in the body,” he stated. If sodium is out of steadiness, individuals can have vital well being issues, similar to hypertension or lack of kidney operate.
“[The human body is] intricate, but I think it’s also amazing in its simplicity,” Townsend stated. “The complex interconnected systems that keep us alive — they all depend on a handful of elements. If you think about how complex the human body is, that’s sort of magical.”
Initially revealed on Reside Science.