is an extensive membrane
network of network of cisternae cisternae (sac-like
structures) held together by
the cytosk l e eton.
The phospholipid phospholipid
membrane encloses a space,
the cisternal space (or lumen),
from the from the cytosol cytosol,
is primarily a is primarily a protein protein- and
lipid-manufacturing factory manufacturing factory.
2 distinct types of ER: distinct types of ER:
1) Smooth ER (SER) ) Smooth ER (SER)
2) Rough ER (RER) ) Rough ER (RE