Cell City

1. Cell City Students will be able to use analogies to create a pretend city that works just like the cell.

4. Cell City Link • http://www.summitinc.org/academy/Cell%20City/citylimit.html

5. 1. Highway or Road System • Endoplasmic Reticulum The endoplasmic reticulum (ER) is a series of interconnecting flattened tunnels which are attached to the outer membrane of the nucleus. The ER is the transport network for molecules targeted for certain modifications and specific final destinations.

6. 2. City Border • The cell membrane is found directly inside the cell wall in plants.  It allows things to pass into and out of the cell. Materials like food and oxygen are kept inside the cell. Waste products and excess water are allowed to leave. In that way the cell can maintain correct conditions inside the cell regardless what the conditions may be outside the cell. This is known as a process called homeostasis.

7. 3. Cell Wall • In a plant cell the cell wall is found outside the cell membrane. In an animal cell, the cell membrane forms the outer covering of the cell. • The cell wall is made of a tough material called cellulose and acts like a fence, keeping the cell safe from the environment. It forms a barrier between the living material inside the cell and the environment outside. • The cell wall also provides support for the cell. Animal cells, unlike plant cells, do not have a rigid cell wall.

8. 4. Lumberyard/Construction Site: • Ribosome • The ribosomes are found on the endoplasmic reticulum and floating in the cytoplasm. The ribosome is the protein factory of our cells. Without protein we wouldn't have cell membranes, enzymes, or substance in our bones, but the real construction site of the cell creates the ribosomes!

9. 5. Post Office: • Golgi Apparatus • The Golgi apparatus is a bit like a factory’s customization shop, where the finishing touches are put on products before they are ready to leave and “shipped” to their final destination. The Golgi apparatus attaches carbohydrates and lipids to them.

10. 6. Solar Energy Plant • Chloroplasts, found only in plant cells,are green because they contain chlorophyll. Chlorophyll is what captures the energy of the sun, which can then be used to help produce food for the plant cell in the process of photosynthesis.

11. 7. City Hall: Nucleus The nucleus is the control centerof the cell, acting like the "brain." The nucleus is the largest organelle in a cell and can usually be seen using a light microscope. The nucleus contains the DNA of the cell - the genetic code which allows the cell to reproduce and which allows it to make all the proteins it needs to carry out the normal business of living.

12. 8. Copy Machine/ Blueprints: • Nucleolus • Makes copies of the DNA that is stored in the nucleolus.

13. 9. Fence Around City Hall: • Nuclear Envelope

14. 10. Power Plant: • Mitochondria • The mitochondria are often called the 'power stations' of the cell. The reactions involved are very complex but, put very simply, the mitochondria burn food molecules to release energy. This energy is used by cells to do work. This work may be building new molecules which have a particular function in the body, or it may be to produce movement (muscle cells, for example).

15. 11. Waste Disposal: • Lysosomes are small organelles filled with enzymes. Lysosomes also help break down organelles that outlived their usefulness. Lysosomes perform the vital function of removing debris that might otherwise accumulate and clutter up the cell.

16. 12. Warehouse/ Storage Unit: • Vacuoles are used to transport and store nutrients, waste products and other molecules. The presence of a vacuole enables plant cells to grow larger than animal cells - the expansion of a fluid filled space is a lot less costly in terms of energy expenditure than expansion of a cell full of organelle-containing cytoplasm. Vacuoles are also used for storage of substances which the plant needs, but which may be toxic to the rest of the cell.