1. The Cytomembrane System

2. Components: Endoplasmic Reticulum Golgi Bodies Vesicles
Rough
Smooth
Golgi Bodies
Vesicles
Technically not part of it, but necessary for the Cytomembrane System to function:
Nucleus and nuclear membrane, ribosomes and the cytoskeleton.

3. Functions: Lipids are assembled
Polypeptide chains are modified into final proteins
Lipids and proteins are sorted and shipped

4. The Nucleus
Contains the cell’s genetic information which codes for proteins.
mRNA is transcribed from the DNA in the nucleus, leaves the nucleus.

5. The Nuclear Membrane Bilipid layer
Contains pores which allow large molecules to leave the nucleus.

6. Ribosomes Located in the cytoplasm or attached to the ER
Site of protein synthesis
mRNA is translated to create new protein

7. Free Ribosomes Attached to the ER
Usually make proteins that will be used in the cytoplasm
Attached to the ER
Usually make proteins that will be exported or used in the plasma membrane

8. In the Rough ER
Some proteins have a specific signal which allows them to enter the space within the rough ER
As the protein travels through the ER enzymes attach side chains and the protein become folded

9. In the Smooth ER
Lipids are assembled

10. Materials from the ER are shipped to the Golgi Bodies
Vesicles bud off the ER and travel through the cytoplasm to the Golgi body

11. The vesicles travel through the cytoplasm on motor proteins that travel on the microtubules and microfilaments of the cytomembrane system

12. Golgi Bodies Enzymes finish modifications of proteins and lipids
The materials are then sorted based on where they will be used and the modifications made to them

13. Materials from the Golgi Bodies are enclosed in membranes to form vesicles and then shipped from the Golgi to locations where they are needed.
Vesicles may be excreted or become specific structures such as lysosomes

14. Specialized Cells
Pancreatic cells – have large amounts of rough ER to produce enzymes that are secreted into the small intestine to help digest food
Liver cells – have large amounts of smooth ER where drugs and some toxic substances are inactivated