Endoplasmic Reticulum (ER)
General ER Structure
- "the network within"
- Internal space separate from cytosol.
- Contiguous with the inside of nuclear membrane!
- Two distinct connected regions (smooth and rough ER).
- Arranged as "pipes".
- Synthesis of lipids and carbohydrates.
- Detoxify drugs (liver).
- Secrete steroids (sex hormones).
- Arranged as flattened, stacked sacs.
- Dotted with ribosomes. Ribosomes can become detached.
- Assemble of polypeptides.
- Makes more membranes.
- Polypeptides can be kept inside ER and "budded" off into transport vesicles.