Organization of the Body
with ribosomes on its external face. Te inner nuclear mem-
brane is lined by the
, a network of
shaped proteins that assemble to form intermediate ﬁlaments)
that maintains the shape of the nucleus and acts as a scaﬀold to
organize DNA in the nucleus (Figure 3.29b, bottom).
The Nuclear Envelope
Te nucleus is bounded by the
membrane barrier separated by a ﬂuid-ﬁlled space (similar to
the mitochondrial membrane). Te outer nuclear membrane is
continuous with the rough ER of the cytoplasm and is studded
line of outer
Nuclear pore complexes.
Each pore is ringed
by protein particles.
Surface of nuclear envelope.
The netlike lamina
composed of intermediate filaments formed by
lamins lines the inner surface of the nuclear
Cisterns of rough ER
Three-dimensional diagram of the nucleus, showing the continuity
of its double membrane with the ER.
Freeze-fracture transmission electron micrographs (TEMs).