Cells and the Cell Cycle

 

    

Objectives for today:
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Cytoplasm


* A thick, aqueous solution of salts surrounding the organelles inside the cell membrane.
* Nutrients and minerals spread through the cytoplasm to all parts of the cell.
* The constant motion of this gel-like substance is called cytoplasmic streaming.

 

Nucleus


* The structure inside the cell that directs cell activities.
* Contains the DNA of a cell.
During most of a cell's life cycle, the DNA is spread through the nucleoplasm. The DNA condenses into chromosomes only in preparation for cell division.

 

Ribosome


* The sites of protein synthesis in a cell.
* These small, spherical structures are the most numerous organells in almost all cells.
* Some ribosomes produce protein to be used within the cell and some produce protein that is "exported" to other parts of an organism.
Endoplasmic reticulum
* A membrane system of folded sacs and tunnels in the cytoplasm.
* Rough "ER" is covered with ribosomes. It is common in cells that export proteins and directs the proteins flow.
* Smooth "ER" as few or no ribosomes. It functions as a pathway for molecules to follow.

 

Mitochondria


* Respiration centers of a cell.
* Large organells scattered through most cells, they are most numerous in cells that use a lot of energy like liver and muscle cells.

 

Golgi Apparatus


* A stack of membranes or sacs that acts to prepare substances for export from the cell.
* Once the Golgi apparatus has enclosed the final product in a vesicle, or pouch, the product is sent through the cell membrane

 

Lysosome

* Digestive centers of a cell.
* They produce many different types of enzymes and digest things from food particles to a cell's own worn out parts.

 


Vacuole

* Most common in plant cells, they are storage sites within a cell.

 


Plastid

* Pigment producing organelle in cells.

 

Summary of Organells
Cell Part
Function
Mitochondria
Energy center or "powerhouse" of the cell. Turns food into useable energy (ATP)
Ribosomes
Make protein
Golgi Apparatus
Processes, packages and secretes proteins
Lysosome
Contains digestive enzymes, breaks things down
Endoplasmic Reticulum
Transport, "intracellular highway"
Vacuole
Stores water or other substances
Chloroplast
Uses sunlight to create food, photosynthesis (only found in plant cells)
Cell Wall
Provides additional support (plant and bacteria cells)

 

 

Get a copy of the above diagram and lable it.

 

 

Test your knowledge of the functions of cell organelles