1. 4.6 The nucleus is the cell’s genetic control center
ORGANELLES OF THE ENDOMEMBRANE SYSTEM
4.6 The nucleus is the cell’s genetic control center
The largest organelle is usually the nucleus
The nucleus is separated from the cytoplasm by the nuclear envelope
The nucleus is the cellular control center
It contains the DNA that directs the cell’s activities

2. Two membranes of nuclear envelope
NUCLEUS
Chromatin
Two membranes of nuclear envelope
Nucleolus
Pore
ROUGH ENDOPLASMIC RETICULUM
Ribosomes
Figure 4.6

3. Ribosomes-non-membrane bound organelles
Ribosomes are free or attached to the endomembranous system of endoplamic reticulum
They are where proteins are built.

4. The endomembrane system is a collection of membranous organelles
4.7 Overview: Many cell organelles are related through the endomembrane system
The endomembrane system is a collection of membranous organelles
These organelles manufacture and distribute cell products
The endomembrane system divides the cell into compartments
Endoplasmic reticulum (ER) is part of the endomembrane system

5. 4.8 Rough endoplasmic reticulum makes membrane and proteins
The rough ER manufactures membranes
Ribosomes on its surface produce proteins 1 2 3 4
Transport vesicle buds off
Ribosome
Sugar chain
Glycoprotein
Secretory (glyco-) protein inside transport vesicle
ROUGH ER
Polypeptide
Figure 4.8

6. 4.9 Smooth endoplasmic reticulum has a variety of functions
Smooth ER synthesizes lipids
In some cells, it regulates carbohydrate metabolism and breaks down toxins and drugs

7. SMOOTH ER ROUGH ER Nuclear envelope Ribosomes SMOOTH ER ROUGH ER
Figure 4.9

8. 4.10 The Golgi apparatus finishes, sorts, and ships cell products
The Golgi apparatus consists of stacks of membranous sacs
These receive and modify ER products, then send them on to other organelles or to the cell membrane

9. The Golgi apparatus Golgi apparatus Golgi apparatus
“Receiving” side of Golgi apparatus
Transport vesicle from ER
New vesicle forming
“Shipping” side of Golgi apparatus
Transport vesicle from the Golgi
Figure 4.10

10. 4.11 Lysosomes digest the cell’s food and wastes
Lysosomes are sacs of digestive enzymes budded off the Golgi
LYSOSOME
Nucleus
Figure 4.11A

11. Lysosomal enzymes digest food destroy bacteria
recycle damaged organelles
function in embryonic development in animals

12. Transport vesicle (containing inactive hydrolytic enzymes)
Rough ER
Transport vesicle (containing inactive hydrolytic enzymes)
Plasma membrane
Golgi apparatus
Engulfment of particle
Lysosome engulfing damaged organelle
“Food”
LYSOSOMES
Digestion
Food vacuole
Figure 4.11B

13. 4.12 Connection: Abnormal lysosomes can cause fatal diseases
Lysosomal storage diseases are hereditary
They interfere with other cellular functions
Examples: Pompe’s disease, Tay-Sachs disease

14. 4.13 Vacuoles function in the general maintenance of the cell
Plant cells contain a large central vacuole
The vacuole has lysosomal and storage functions
Central vacuole
Nucleus
Figure 4.13A

15. Protists may have contractile vacuoles
These pump out excess water
Nucleus
Contractile vacuoles
Figure 4.13B

16. 4.14 A review of the endomembrane system
The various organelles of the endomembrane system are interconnected structurally and functionally
Transport vesicle from Golgi
Transport vesicle from ER
Rough ER
Plasma membrane
Vacuole
Nucleus
Lysosome
Golgi apparatus
Smooth ER
Nuclear envelope
Figure 4.14