Cell

I am the command center of the cell

Separated from cytoplasm by nuclear envelope

Consists of double layer of membrane

Nuclear pores permit exchange between nucleoplasm & cytoplasm

Site of protein synthesis

May be located: On the endoplasmic reticulum, or free in the cytoplasm, either singly or in groups called polyribosomes

Composed of rRNA

I modify proteins

I synthesize lipids

I package molecules