1.Site of rDNA gene transcription and rRNA processing

2. Initial stages of ribosomal subunit assembly (the final assembly occurs in the cytosol)

-most obvious nuclear subdomain

-irregular shaped

-dense and granular in appearance

-not membrane bound

-size and number depend on the metabolic activity of the cell 

1.RCC1

2.Located in the nucleus

3.Exchanges GDP for a GTP

1.Ran-Gap1

2.Located in the cytoplasm

3.Hydrolizes GTP to GDP

1.Highly organized, fluid filled interior of the nucleus

2.Greater than 30 subdomains(specialized regions/not membrane bound)

1.It's where transcription factors are concentrated

2.In the nuceloplams. Chromatin(active genes) from different subdomains extend into the interchromosomal channels. 

1. Subdomains where mRNA splicing factors are concentrated (where pre-mRNA processing occurs)

2.In the nucleoplasm. In interchromosomal channels near transcription factories

1.ER

2.Golgi

3.Endosomes

4.Lysosomes

5.Secretory granules

6.Plasma Membrane

1.Nucleus(can be debated)

2.Peroxisomes

3.Mitochondria

4.Chloroplasts

1.Structurally

2.Functionally

1.contain a particular set of proteins

2.perform a unique set of activities

3.provide compartmentalisation and functional diversity

4.conserved in eukaryotes

5.dynamic structures

From ER to Golgi to Endosomes to Lysosome

(in some instances they can travel from the endosome to the plasma membrane)

1.Constitutive Secretion

2.Regulated Secretion

1.Mediates the shape of tubules and cisterane in the ER.

2.Unique integral membrane proteins that posses a hair pin(v) shaped secondary structure and regulate ER membrane curvature

1.Rough ER

2.Smooth ER

1.A subdomain of the ER

2.Composed of mostly cisternae with bound ribosomes. 

3.Involved in protein and membrane phospholipid synthesis

1.A subdomain of the ER

2.mostly curved tubules lacking ribosomes

3.Involved in Ca2+ storage and horomone synthesis

False: There are greater than 20 other subdomains

1.Outer Nuclear Membrane

2.Mitochondira and Plasma Membrane Associated Membranes (MAMS and PAMS)

3.ER exit sites (ERES)

1.free ribosome in cytosol

2.ER membrane bound ribosomes

1.Remain in the cytosol ex.glycolytic enzyme

2.Post translationally targets another organelle (ex.mitochondria, chloroplats, nucleus)

1. Remains in the RER ....goes to another RER subdomain

2.Goes to another compartment of the endomembrane system (golgi, endosome, lysosome, pm etc)

It is a chaperone found in the ER.They bind to nascent proteins and mediate their properly folding and oligometric assembly (prevent protein aggregation).

Ex.BiP, calnexin,calreticulin

1.Signal Sequence cleavage by signal peptidase

2.Initial Stages of Glycosylation

3.Protein folding and assembly

4.Quality Control

1.Assists in binding with other macromolecules

2.Assists in protein folding

3.Important in intracellular trafficking-targets protein to specfic subcellular destination

1.Core glycosylation

2.Core modification