Biominerals #5 – Which way is up?

It's the last of our run of biomineral posts – and provides a very fundamental job for some unicellular life.

What does it look like?

Red atoms are oxygen, yellow sulfur and green are the barium atoms. Image generated by the VESTA (Visualisation for Electronic and STructural analysis) software http://jp-minerals.org/vesta/en/

What is it?

We sense gravity through a complicated networks of channels and fluids in our ears and close to our brains.But many other smaller organisms don't have this luxury - they just don't have the space. How do you tell what way is up and down, when you're only made of one cell? So some unicellular organisms, it is thought, make tiny crystals of dense material, like barite, which they keep inside their cell walls. The idea is that they can sense which way is up, by noting where the crystals are in their bodies!

Where did the structure come from?

The crystal structure of Barite is #1000037 in the Crystallography Open Database.

Tags: sulfate   mineral   biomineral   barium