Both bacteria and protists have cell membranes made of chemicals called phospholipids.
Furthermore, all the living organisms belong to one of the cell groups- prokaryotes vs eukaryotes.
Abiotic nitrogen fixation occurs as a result of lightning or by industrial processes.
Plants cells also have a rigid outer wall in addition to a cell membrane.
Prokaryotes might be able to eat almost anything, but these eukaryotes have other advantages.