What are the functions of the cell membrane, cytoplasm and nucleus?

Cells are comprised of a cell membrane, organelles and
nucleus. The cell membrane holds the cell's internal contents from its environment. The
cell membrane is comprised of two layers of fat. The cytoplasm is a liquid in which the
various organelles of the cell are suspended. The cytoplasm keeps organelles in place.
It also allows different materials to flow from one organelle to another. The nucleus of
a cell contains genetic material. DNA, RNA and mitochondria replicate in the nucleus.
The nucleus also produces and replicates proteins, and sends the proteins to other parts
of the cell.