1. Cell Structure & Function

2. The Cell
The cell is the smallest unit of life that can carry out life processes.

3. Cellular Organization
Section 2 Introduction to Cells
Chapter 4
Cellular Organization

4. Discoveries Leading to The Cell Theory
Robert Hooke – observed cork through a light microscope.
Anton Van Leewenhoek – observed LIVING cells.
Theodor Schwann – 1839 –animals are made of cells
Rudolf Virchow – 1855 – all cells come from other cells.
Matthias Schleiden – 1883 –plants are made of cells.

5. The Cell Theory The cell theory states that:
all living organisms are made of one or more cells
cells are the basic units of structure and function
cells come only from pre-existing cells

6. Prokaryotic Cell Prokaryotic- Do not have a nucleus
Do not have internal membrane-bound structures
Most unicellular organisms are prokaryotes.
Bacteria

7. Eukaryotic Cell Eukaryotic- Has a nucleus
Has internal membrane-bound structures
Most multicellular organisms are eukaryotes.
Yeast and algae (unicellular, eukaryotes)
Plant and animal

8. Cilia and Flagella Flagella-long, whip-like projections
Aid in movement and feeding
Composed of microtubules
Cilia-short, numerous hair-like projections that move in a wavelike motion

9. Organelles “little organs”
Specialized parts within a cell that has a specific function

10. Features Common to Cells:
Cytoplasm –
Gel like material that protects, supports and suspends organelles.

11. Features Common to Cells:
Cell membrane – Semi-permeable
Controls what enters and leaves the cell. This helps to maintain cellular homeostasis.

12. Structure of the Plasma Membrane
Phospholipid Bilayer -2 layers ofphospholipids.
Phospholipid- phosphate head attached to two lipids (fattyacid tails).
Polar phosphate group allows membrane to interact with its environment.
Fatty acid tails create a water-insoluble layer in the middle which is non-polar.
Fluid mosaic model-membrane is flexible
Cholesterol-keeps fatty acid tails from sticking together
Transport proteins-allow needed substances to move through the membrane

13. Parts of the Cell
Chapter 4

14. Nucleus Nucleolus-makes ribosomes “Command center”
Ribosomes-site where proteins are made
Can be found floating in the cytoplasm or attached to endoplasmic reticulum
“Command center”
Contains genetic material:
Chromosomes
DNA

15. Endoplasmic Reticulum (ER)
Smooth Endoplasmic Reticulum (SER)
No ribosomes
Produce and store lipids
Series of folded membranes allow a large amount of work to be done in a small amount of space
Transportation unit for the cell
Rough Endoplasmic Reticulum (RER)
Ribosomes attached
Protein synthesis

16. Golgi Apparatus Vesicles
Flattened tubular membranes
Packaging plant
Modify, sort, package, and transport proteins throughout the cell

17. VACUOLES Storage areas Temporary storage of materials
Store food, enzymes, waste, water
Plant cells have one large vacuole.
Animal cells have many small vesicles.

18. LYSOSOMES Contain digestive enzymes
Digest excess or worn organelles, food particles, viruses, and bacteria
Surrounded by membrane that prevents it from destroying the cell
Can burst causing cell death

19. Mitochondria Chapter 4 converts food into energy Cell “Powerhouse”
Number of mitochondria depends upon the function of the cell
Ex: muscles cells have more mitochondria than fat cells

20. Centriole
Help with cell reproduction
Only found in animal cells

21. Chloroplast Located in plant cells, some bacteria, and protists.
Capture light energy to produce and store food
Contain chlorophyll-green pigment that traps light energy

22. Features Common to Cells:
Cytoskeleton – tiny fibers that give structure and support to the cell.

23. Cell wall Rigid outer covering PLANT CELLS
Located outside the cell membrane
Provides support and protection
Helps produce turgor pressure

24. Animal Cell
Plant Cell

25. Plant cell vs. Animal Cell

26. Plant vs. Animal Cells Plant Animal Has chloroplasts
Large central vacuole
Has cell wall
No centrioles
No chloroplasts or cell wall
Small vacuoles
Has centrioles