1. Building Blocks of Life
CELLS
Building Blocks of Life
Martin 2005

2. Prokaryotic Cells Prokaryotic cells Very simple
Few internal structures
DNA is NOT enclosed in a nucleus
NO membrane-bound organelles
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3. Examples of Prokaryotic Cells
Photos: Daniel Kunkel
Martin 2005

4. Eukaryotic Cells Eukaryotic Cells Very complex
Many internal structures
DNA is enclosed in a nucleus
Many membrane-bound organelles like mitochondria and Golgi bodies
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5. Examples of Eukaryotic Cells
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6. Cell Membrane Cell membrane:
The protective layer around all cells. The cell membrane controls what goes in and what goes out of cells.
The Fence
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7. Cell Wall
Cell Wall:
Tough, rigid outer covering found in plants, algae, fungi, and bacteria. Animal cells do not have cell walls. Cell walls protect and support.
The Brick Wall
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8. Cytoplasm
Cytoplasm:
The gel-like material inside cells. This is where many of the chemical reactions take place
The Filler
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9. The Cytoskeleton Cytoskeleton:
Helps the cell maintain OR change its shape. Some organisms move by stretching and contracting the cytoskeleton.
The Bones
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10. The Nucleus
Nucleus:
Directs all the activities of the cell. The DNA in the nucleus contains the instructions for everything the cell does. The nucleus is surrounded by its own membrane.
The Brain
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11. The Mitochondria Mitochondria:
Break down food (sugars) into carbon dioxide and water. This reaction releases the stored energy in the food,
The Furnace
The Powerhouse
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12. Mitochondria at Work
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13. The Chloroplasts Chloroplasts:
Use the energy from the sun to convert carbon dioxide and water into sugars (food). Animal cells do not have chloroplasts.
The Sugar Factory
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14. Chloroplasts at Work
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15. The Endoplasmic Reticulum
One long membrane that connects the nuclear membrane to the cell membrane. It has many folds. Proteins and other chemicals move along this membrane.
The Highway System
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16. The ER at Work
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17. The Ribosomes Ribosomes:
Made in the nucleolus, these organelles move out of the nucleus to the cytoplasm. They have no membranes that surround them. They make proteins.
The Protein Factory
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18. The Golgi Bodies Golgi Bodies:
These organelles sort, fold, package, and deliver proteins and other chemicals to areas inside and outside the cell.
The UPS Store: Sort, Pack, and Deliver
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19. Golgi Bodies at Work
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20. The Lysosomes Lysosomes:
These contain digestive chemicals (enzymes) that break down food particles, waste products, and damaged cell parts for recycling. These are much more important in animal cells.
The Recycling Center
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21. The Vacuoles Vacuoles:
These temporarily store water, food, and waste materials. These are very large and very important in plant cells. They also provide support.
The Closet
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22. References http://library.thinkquest.org/C004535/introduction.html
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23. Gallery of Cells
Martin 2005