1. The Cell Membrane:
“Skin” that surrounds cell
Selectively permeable
Phospholipid bilayer
Many cell organelles have
membrane

2. Cytoplasm (Cytosol) The liquid inside the cell
Helps to support cell structures
Provide protective buffer

3. Cytoskeleton gives a cell shape holds organelles inplace
Lets cell move in space by contracting and expanding (microfilaments made of protein actin).
Holds organelles in place and anchor nucleus (intermediate filaments)

4. Mitochondrion The “powerhouse” of the cell Double-membrane
Has its own DNA and ribosomes
Use chemical energy from primarily sugar to make the energy for the cell to do various metabolic tasks.
The main molecule that provides chemical energy is adenosine tri- phosphate (ATP).

5. NUCLEUS The control center of cell Source of genetic information
Instructions for protein production which controls cell functioning.
Almost always near center of cell.

6. NUCLEOLUS Dark area in center of nucleus Makes materials for ribosomes
Defective nucleoli evident in Parkinson’s and Huntington’s diseases.

7. Endoplasmic reticulum
Attached to the nucleus by its membranes.
Two parts: the smooth endoplasmic reticulum (SER) and the rough endoplasmic reticulum (RER).
SER releases lipids, such as hormones, that are used both in the cell and in other cells.
RER looks rough because it is studded with ribosomes and functions in making proteins.

8. Golgi Apparatus
Modifies proteins by adding signaling sugars onto surface of protein.
Unmodified protein arrives at Golgi inside a transport vesicle.
Fuses with Golgi and is modified as it travels through Golgi
Golgi membrane pinches off with modified protein inside.

10. Protein Targeting & Disease
Different types of proteins are housed in different parts of the cell where they can carry out their specific functions.
Other proteins are secreted.
If proteins end up in the wrong place or don’t get to the right place this can lead to abnormal cell function and/or serious diseases.

11. Perioxisomes Vesicles that contain oxidative enzymes
Breaks down fatty acids, some amino acids, and toxic hydrogen peroxide.
Look similar to lysosomes but bigger
Found near mitochondria and chloroplasts while lysosomes can be found anywhere in the cell.

12. Found in many Animal Cells - Centrioles
Organize the spindle during cell division.
Consist of 9 groups of microtubules; each group has three microtubules.
Therefore there are 27 microtubules in one centriole.
Centrioles are always arranged perpendicular to each other.

13. Found in many Animal Cells -Flagella
9 + 2 arrangement of microtubules
Used for cell movement

14. Found in many Animal Cells -Cilia
Similar in structure to the flagella, but they tend to be shorter
9 + 2 arrangement of microtubules
Found in groups on the cell surface.
In single-celled organisms, they are used to move the cell.
In the human body, used to move substances across the cell surface (e.g. cilia can be found on cells lining the trachea. These cells help to move mucus and trapped particles away from the lungs.

15. Found in animal cells - Lysosomes
Recycling centers of cell.
Contain hydrolytic enzymes which break nutrient particles into smaller pieces so that other organelles can use these fragments as a source of energy.
They destroy bacteria and organic debris that enter cell from extracellular fluid.
Break down damaged organelles, freeing components for re-use.
Rarely found in plant cells because the central vacuole fulfills the recycling function in plant cells.

16. Found only in plant cells: Chloroplast
Surrounds the outside of a plant’s cell membrane
Attaches cells to neighboring cells.
The wall is made of a rigid polysaccharide called cellulose
Gives plant cells shape and structure .
It prevents cell from bursting when too much water is available (e.g. rainy seasons).
Turgor pressure is pressure that water puts on cell wall

17. Found only in plant cells: Central Vacuole
Found near the middle of the cell.
Stores water and other materials in these storage tanks, keeping them separate from cytosol.
Central vacuoles perform the same functions as lysosomes, breaking down nutrients and organelles into usable energy components

18. The History of the Cell Theory