Hydroxyapatite is the major component of bone that contributes to its hardness.
<span>adding a unit to move a susceptible group enough to prevent metabolism is known as shifting.
These phenomena happen especially for liposoluble organism circulating in blood like drugs an hormones.
these molecules circulating blood can be divided into two forms :
The free-form: which is the active part, it circulates freely in the blood, but are easily metabolised.
The bound form: it can be bound to other molecules from the organisms depending on its affinity like proteins (albumin, glycoproteins). this form is not active but is prevented from metabolism.
Competition for bounding proteins can happen between two drugs for example. If they have a different degree of affinity for proteins, then the most affine will displace the less affine from the protein and bound it, and that is call shifting</span>
