biochemistry - Which hydroxyl from either the phosphate or the glycerol is taken during synthesis of a phospholipid head?

The oxygen anion in the phosphate group is likely to be bonded with a hydrogen cation and thus forming a hydroxyl.

When the phosphate group is condensed with glycerol to make a phospholipid, is the hydroxyl from the glycerol molecule taken or the hydroxyl from the phosphate group taken?

I believe it's related to the difference of electronegativity of oxygen and phosphorus which causes unequal sharing of electrons between atoms, thus making a hydroxyl from one side easier to get taken off than the hydroxyl from the other side is.