3.6 The Nucleus

• The largest and most conspicuous structure in a cell

• The control center for cellular operations

• stores all the information needed to control the synthesis of the more than 100,000 different proteins in the human body

Consisting of a double membrane surrounds the nucleus and separates its fluid contents (nucleoplasm) from the cytosol

Pores large enough to allow movement ions and molecules, yet small enough to regulate the transport of proteins and RNA

Organelles that synthesize ribosomal RNA (rRNA)

Assemble the small and large ribosomal subunits

They pass through the nuclear pores into the cytoplasm

Dense structures, composed of tightly coiled DNA strands and associated histones, that become visible in the nucleus when a cell prepares to undergo mitosis or meiosis; each normal human somatic cell contains 46 of them

In cells that are not dividing, the nucleosomes are loosely coiled, forming a tangle of fine filaments known as...