1. Cell Structure and Function

2. POP QUIZ 10/9/12 What characteristics define a prokaryote?
What is the endosymbiotic theory?
What is the function of the Endoplasmic reticulum? (both)

3. History of the cell
In 1665, Robert Hooke was the first to view cells from cork (dead plant material). He called them “cells” because they looked like tiny rooms.
Anton van Leeuwenhoek saw tiny living organisms in water in 1675.

4. In 1838, Matthias Schleiden determined that plants are made up of cells.

5. In 1839, Theodor Schwann determined that animals are made up of cells.

6. In 1855, Rudolf Virchow concluded that new cells are produced from the division of existing cells.
Lynn Margulis proposed that mitochondria and chloroplasts were descended from ancient symbiotic prokaryotes. This is called the Endosymbiotic Theory

7. The Cell Theory All living things are composed of cells.
Cells are the basic units of structure and function in living things.
New cells are produced from existing cells.

8. Types of Cells
Two kinds of cells depending on whether they have a nucleus
Eukaryote
Prokaryote
Genetic material

9. 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.

10. Prokaryotic Cells

11. 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.

12. Eukaryotic cell structure
Two major parts:
Nucleus
Cytoplasm-portion of the cell outside the nucleus

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

14. 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.
Small dense region called a nucleolus where ribosomes are made.

15. Nucleus-The control center
Function:
Contains almost all of the cell’s DNA for coding proteins and other molecules.
DNA is found on chromosomes which contain genetic information.

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

17. Endoplasmic Reticulum
Function:
Site where lipid parts of cell membrane are made, along with proteins and other materials to export from the cell. In addition, the smooth ER detoxifies drugs and toxins in the cell
Structure:
Membranous system
Rough ER- has ribosomes on surface to assemble proteins
Smooth ER-NO ribosomes on surface

18. Golgi Apparatus Function: Structure:
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.
Structure:
Stack of closely packed membranes

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

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

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

22. Chloroplasts – Energy in Plants
Function:
Captures energy from the sun (solar energy) and changes it into food (chemical energy) for plants (photosynthesis)
Structure:
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!

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

24. Flagellum- long, whip-like structure made of microtubules; swim through fluid

25. Cilia- small hair-like structures made of microtubules; beat rhythmically to move fluid outside the cell. This propels the cell.

26. Centrioles- pair of cylindrical arrangement of microtubules found perpendicularly to each other; help in ANIMAL CELL division
Region around centrioles called centrosome

27. Cell Membrane Function: Structure:
Regulates what enters and leaves the cell
Provides protection and support
Structure:
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

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