1. Cellular Organelle

2. Cell Wall Not found in animal cells
In plants, the cell wall provides support for the cell (no skeleton)
Is made of cellulose, a tough, stringy macromolecule

3. Cell Membrane
Function: Control the movement of substances in and out – this makes it selectively permeable.
Made mostly of phospholipids, which have a hydrophobic tail and a hydrophilic head, like this:
Head
Tail

4. Cell membrane, continued…
These lipids form a “lipid bilayer”:
Bilayer is flexible, giving the cell different shapes.
Some chemicals stick out of the bilayer to allow for cell identification. Some are proteins that act as channels to allow big molecules (like sugar) to go through.

5. Cell membrane, still…
Because the cell membrane is so flexible, and it has a broken, disjointed look to it, the model of the cell membrane is called:
The Fluid Mosaic Model

6. Vacuole Sac filled with water and nutrients
Function in plants: To give the plant support by providing Turgor pressure
When the vacuole is full, it pushes the organelle towards the cell wall, which expands the cell and holds the plant upright.
High Turgor Pressure
When the vacuole lacks water, the plant wilts
Low Turgor Pressure

7. Endoplasmic Reticulum (ER)
Extensive membrane system
Rough ER, shown here, is covered with ribosomes
Function: Transports, modifies and stores proteins
generally internal transport
Smooth ER
Function: Transport, modification & storage of lipids
creates steroid hormones and other macromolecules.

8. The Golgi Apparatus Flattened sacs Function:
Create lysosomes and other protein-filled vesicles
Stores, modifies & packages protein for transport
The process of packaging proteins happens through endocytosis

9. Active Transport: Two Types
Endocytosis:
Membrane wraps around proteins, then pinches off.
Always refers to a vesicle (protein sac) ENTERING the cytoplasm.
Exocytosis:
The golgi apparatus receives the proteins from the Endoplasmic Reticulum, packaged in vesicles
The vesicle membrane merges with the GA membrane, and releases the proteins into the GA.
Always refers to a vesicle LEAVING the cytoplasm
See handout
Bio11 CD
WWW

10. Lysosomes Only found in animal cells!
Vesicles filled with digestive enzymes (proteins that speed up reactions)
Function:
Breakdown food particles and foreign objects like bacteria

11. Ribosomes Found all over cell: Function: Millions found in most cells.
on Rough Endoplasmic Reticulum
in cytoplasm
in mitochondria
in chloroplasts
Function:
Provides a site for protein synthesis
Millions found in most cells.

12. END