Final answer:
Phosphobicarbonates are not a component of the plasma membrane; the plasma membrane is primarily composed of phospholipids, peripheral proteins, glycolipids, and glycoproteins.
Step-by-step explanation:
The constituent that would not be a part of a plasma membrane among the options given is phosphobicarbonates. The plasma membrane's principal components include phospholipids which form the bilayer, peripheral proteins which are part of the cell's recognition sites, glycolipids which are carbohydrates attached to lipids, and glycoproteins which are carbohydrates attached to proteins. Phosphobicarbonates are not a known component of cell membranes and do not fit within the fluid mosaic model of the plasma membrane structure.