What does a cell membrane keeps a cells

The cell membrane is the lipid bilayer that encloses the cell, and therefore the cytoplasm which in turn contains the rest of organelles we can find in a cell.

All types of cells have a cell membrane but in plant cells it is no the outermost layer, being enclosed by the cell wall. In animal cells instead, the cell membrane is the outemost layer.

Hope it helped,

BioTeacher101

a symbiotic relationship with the mitochondria