why is phosphorus so important to our bodies?


I’ve been learning a lot about metabolism and nutritional biochemistry and I’ve noticed that phosphorus is involved in almost all of the processes from substrate breakdown, enzymatic reactions, etc.

Why is that? Does phosphorus have unique chemical properties that make it so integral for our bodies?

In: 14

Still TLDR; opposites attract, likes repel and chemistry follows the same rules.

TLDR; phosphorus is mostly found in the body as a chemical called phosphate which is very negatively charged. That’s because phosphorus likes to give away electrons. That negative charge means it’s great for storing energy, means it likes to be closer to water which gives DNA it’s double helix shape, and the negative charge means calcium (which is positively charged) holds onto it very strongly which is why bone is so hard to break.


You know how mitochondria are the powerhouse of the cell? They basically turn sugar into energy your cell can use. That energy has to be stored in batteries – and the battery that your cells use the most is called ATP (adenosine tri-phosphate). Every ATP molecule has a tail made of 3 phosphate ions.

You’re exactly right – the thing that makes phosphate perfect for storing energy is exactly is it’s structure. Phosphate is made of a phosphorus ion surrounded by 4 oxygen ions. Oxygen LOVES electrons and phosphorus has a lot of electrons it doesn’t really care about, so they’re a perfect combo. But what ends up happening is the oxygens end up very negatively charged (basically they have too many electrons around them).

That gives the phosphorus molecule a very negative charge. You know how if you take a magnet and try to push the negatives ends together, it gets takes a ton of effort? Now imagine if you put a really strong spring in between the magnets – as they try to pull apart they’re going to stretch the spring and if you were to cut one of the magnets loose, you end up with the spring snapping back with a ton of energy.

That’s exactly what your mitocondria are doing – when they stick the phosphate groups together you end up with a very high energy chemical bond (the spring) holding the two phosphate groups together. When your body wants energy to perform some task, like making your bicep contract, it cuts the bond and uses the energy of the spring snapping to power a chemical reaction.

Because ATP is so ubiquitous, it’s used for basically everything in your body that requires energy. Some reactions use GTP – guanosine triphosphate but the idea is the same since it’s a chain of three phosphates.

Okay so that’s one reason why phosphate is really useful (and it’s probably the most complicated). The other big one is that it forms the backbone of DNA. DNA has two parts – it has a backbone made of phosphate and sugar and it has a middle part that’s made of chemicals called “bases”.

You know how phosphate really negatively charged? Things that have negative or positive charges really like being near water molecules. Since the backbone of DNA is negatively charged it gets pulled to the outside of the DNA structure. The bases (the other part of DNA) don’t like water as much, so they get pushed into the middle where they can be protected.

I guess the other place where phosphorus is found is in bone. that’s just because calcium and phosphate really like to bind eachother and they can form a crystal called hydroxyappitite which is extremely strong. Hydroxyapatite is what makes bone hard and it’s like that because phosphate is negatively charged, and calcium is positively charge – opposites attract and so they bind eachother very tightly.

Source: am medical student