1. Cell Structure and Function

2. The cell theory grew out of the work of many scientists and improvements in the microscope.
Many scientists contributed to the cell theory.
More was learned about cells as microscopes improved.

3. The cell theory grew out of the work of many scientists and improvements in the microscope.
Many scientists contributed to the cell theory.
More was learned about cells as microscopes improved.
The cell theory is a unifying concept of biology.

4. Early studies led to the development of the cell theory.
The Cell theory has three principles.
All organisms are made of cells.

5. Early studies led to the development of the cell theory.
The Cell theory has three principles.
All organisms are made of cells.
All existing cells are produced by other living cells.

6. Early studies led to the development of the cell theory.
The Cell theory has three principles.
All organisms are made of cells.
All existing cells are produced by other living cells.
The cell is the most basic unit of life.

7. Prokaryotes Genetic material is not in a nucleus
Less complicated and smaller than eukaryotic cell
Example: Bacteria
**An organism made of a prokaryotic cell is called a prokaryote.

8. Prokaryotic Cells

9. Eukaryotes
Genetic material is contained in a nucleus and separated from the rest of the cell
More complex and larger than prokaryotic cells
Example: Plants, animals, fungi, protists
**An organism made of eukaryotic cell(s) is called a eukaryote.

10. Eukaryotic cells
Diatoms (algae)
Root tip
Neuron
Uterine cells

11. Eukaryotic cell structure
Two major parts:
Nucleus
Cytoplasm-portion of the cell outside the nucleus that contains organelles (parts or “organs” of the cell)

12. Nucleus-The control center
Structure:
Surrounded by a double membrane called a nuclear envelope. It is dotted with many nuclear pores to allow materials (RNA, proteins, etc) in and out of the nucleus.

13. Nucleus
Function:
Contains almost all of the cell’s DNA for coding proteins and other molecules.
DNA is found on chromosomes which contain genetic information.
The Control Center of the cell!

14. Nucleolus Structure: Function:
Small dense region in the center of the nucleus
Function:
where ribosomes are made.

15. Ribosomes Structure: Function:
Small pieces of RNA and protein found throughout the cell.
Two subunits.
Function:
Site of protein synthesis.

16. Rough Endoplasmic Reticulum
Structure:
Membranous system
Rough ER- has ribosomes on surface to assemble proteins
Continuous with the nuclear envelope
Function:
Site where lipid parts of cell membrane are made, along with proteins and other materials to export from the cell.

17. Smooth Endoplasmic Reticulum
Structure:
Membranous system
NO ribosomes on surface
Function:
Synthesis of lipids and phospholipids for membranes
Detoxifies drugs and toxins in the cell

18. Golgi Apparatus Structure: Function: Stack of closely packed membranes
Modify, sort, and package proteins and other materials from the ER for storage in the cell or release from the cell. It puts the finishing touches on proteins.

19. Lysosomes Structure: Function:
Small sac, filled with digestive enzymes
Function:
Breakdown of lipids, carbohydrates and proteins into small molecules to be used by the rest of the cell
Breakdown used up organelles
Gets rid of all “stuff” in the cell
The “Clean-up crew”

20. Vacuole Structure: Function: Sac-like
Plant cells have one large central vacuole
Animal cells have many small vacuoles
Function:
Stores water, salts, proteins and carbohydrates

21. Mitochondria Structure: Function:
Enclosed by two membranes with the inner folded membrane, called cristae.
Contains it’s own DNA (Evidence for the Endosymbiotic Theory)
Function:
Convert chemical energy in food into materials easier for the cell to use. This is called cell respiration.

22. Chloroplasts Structure: Function: Surrounded by two membranes
Stacks of membranes inside called thylakoids.
Contains own genetic information like mitochondria
Contains green pigment called chlorophyll
Not found in animal cells!
Function:
Captures energy from the sun (solar energy) and changes it into food (chemical energy) for plants (photosynthesis).

23. The History of the cell continued
In 1967, Lynn Margulis proposed that mitochondria and chloroplasts were descended from ancient symbiotic prokaryotes. This theory is called the Endosymbiotic Theory!
Click on image to view video

24. Cytoskeleton- structure and support
Two types: microfilaments and microtubules- made of proteins
Function:
Helps maintain cell shape
Helps with movement of the cell (i.e. flagella and cilia)

25. Flagellum Structure: Function:
long, whip-like structure made of microtubules
Function:
Allows the cell to swim through fluid

26. Cilia Structure: Function:
small hair-like structures made of microtubules; beat rhythmically to move fluid outside the cell.
Function:
This propels or anchors the cell.

27. Centrioles Structure Function
Pair of cylindrical arrangement of microtubules found perpendicularly to each other
Region around centrioles called centrosome
Function
help Divide the DNA in ANIMAL CELL division

28. Cell Membrane Structure: Function:
Double membrane called a lipid bilayer
Flexible structure that forms a strong barrier between the cell and its surroundings
Phospholipids with integral proteins and cholesterol
Function:
Regulates what enters and leaves the cell
Provides protection and support

29. Cell Wall Structure: Function: Lies outside the cell membrane
Made of structural carbohydrates
Found in plants, algae, fungi and many bacteria
NOT FOUND IN ANIMAL CELLS!
Function:
Provides support and protection for the cell

30. Levels of organization (smallest to largest)
1. Cells
2. Tissues: group of similar cells with specific function
Four types: muscle, epithelial, nervous, connective tissue
3. Organs: groups of tissues working together
4. Organ systems: a group of organs that work together to perform a specific function
Examples: Nervous system, digestive system