Here are the main parts of a human cell: Cell membrane: This is the outermost layer of the cell and it protects the cell from its surroundings. It also allows certain molecules to enter and exit the cell. Cytoplasm: This is the jelly-like substance that fills the cell and contains all of the organelles. Nucleus: This is the control center of the cell and contains the cell's DNA. Mitochondria: These are the "powerhouses" of the cell and produce energy for the cell to use. Ribosomes: These are tin