FC: THE CELL BOOK Steven Sun
1: Welcome To The Cell World
2: The cell membrane is a thin, double layer consisting of fatty lipids and protein that separates the cell interior from its surroundings. As the picture shows, the cell membrane is made up of phospholipids (magenta and green), proteins (orange and red), and carbohydrates (black). Carbohydrates can be attached to either the phospholipids or the proteins in the cell membrane. If it's an animal cell, the membrane is the outermost layer of the cell. If it's a plant cell, the membrane is inside the cell wall. The cell membrane is like a border guard. It controls what goes in and out of a cell. The protein on a cell membrane transport messages to the organelles inside a cell. The membrane also protects all the organelles inside a cell to make sure they work properly.
3: The cell wall is the tough, usually flexible but sometimes fairly rigid layer that surrounds some types of cells. The cell walls are found in plants, bacteria, fungi, algae, and some archaea. Animals and protozoa do not have cell walls. Cell walls are made of sturdy materials that provide strength so cells can maintain their shape and live in harsh environments. Scanning electron micrographs of The cell wall is like the wall diatoms showing the external of a house. appearance of the cell wall | Interaction between the cell membrane and the cell wall: The cell wall works with the cell membrane to regulate molecules going in and out of the cell.
4: The cytoplasm is a small gel-like substance residing between the cell membrane holding all the cell's internal organelles, except for the nucleus. Cytoplasm is found in animal and plant cells. It is the where the nutrition and important chemicals for the cell are stored. Cytoplasm plays a vital role in an animal or plant cell. A transmission electron micrograph of the cytoplasm of a plant cell The cytoplasm provides the organelles that float in it with all kinds of nutrients needed, such as protein, to keep them alive. The cytoplasm is like the air in the world that holds everything on earth.
5: The cytoskeleton helps to maintain cell shape. But the primary importance of the cytoskeleton is in cell motility. The internal movement of cell organelles, as well as cell locomotion and muscle fiber contraction could not take place without the cytoskeleton. Cytoskeleton lies just beneath the cell membrane in order to maintain the cell shape and it is found in both prokaryotes and eukaryotes. The cytoskeleton is an organized network of three primary protein filaments: microtubules, actin filaments, and intermediate fibers. In these cells, actin filaments appear light purple, microtubules yellow, and nuclei greenish blue. | Interaction among the cytoplasm, the cytoskeleton and the membrane: The cytoplasm holds the cytoskeleton and gives it nutrients while the cytoskeleton provides a scaffolding for membrane proteins to anchor to. | The cytoskeleton is like the scaffolding of a cell.
6: Endoplasmic Reticulum (ER) is an eukaryotic organelle that forms an interconnected network of tubules, vesicles, and cisternae within cells. Rough ER synthesize proteins, while smooth ER synthesize lipids and steroids, metabolize carbohydrates and steroids (but not lipids), and regulate calcium concentration, drug metabolism, and attachment of receptors on cell membrane proteins. The ER can only be found in eukaryotic cells and they are around the nucleus. | Micrograph of rough endoplasmic reticulum network around the nucleus (shown in lower right-hand side of the picture). | The ER is like the highway system in a cell.
7: The Golgi apparatus is a membrane-bound structure with a single membrane. It is actually a stack of membrane-bound vesicles that are important in packaging macromolecules for transport elsewhere in the cell. The Golgi apparatus is near the nucleus and it is only found in eukaryotic cells. | Micrograph of Golgi apparatus, visible as a stack of semicircular black rings near the bottom. Numerous circular vesicles can be seen in proximity to the organelle | Interaction between the ER and the Golgi apparatus: Rough ER sends simple protein molecules which are transition vesicles to the Golgi Apparatus. The Golgi Apparatus absorbs these transition vesicles through one side of its membrane. It then converts the simple molecules into larger ones. These larger molecules get packaged into secretion vesicles. The Golgi Apparatus then releases these secretion vesicles out of the other side of its membrane into the cytoplasm. | The Golgi apparatus is like FedEx. | Analogy:
8: A vacuole is a membrane-bound sac that plays roles in intracellular digestion and the release of cellular waste products. In animal cells, vacuoles are generally small. Vacuoles tend to be large in plant cells and play a role in turgor pressure. When a plant is well-watered, water collects in cell vacuoles producing rigidity in the plant. Without sufficient water, pressure in the vacuole is reduced and the plant wilts. Vacuoles are found in both animal and plant cells, but they are larger in plant cells than in animal cells. The vacuole is like a warehouse in a cell. | Vacuole in a plant cell | Vacuole in an animal cell
9: Lysosomes contain hydrolytic enzymes necessary for intracellular digestion. In white blood cells that eat bacteria, lysosome contents are carefully released into the vacuole around the bacteria and serve to kill and digest those bacteria. Lysosomes are more common in animal cells than in plant cells. Lysosomes are like recycle bins in cells. | Interaction between vacuoles and lysosomes: In plant cells, when lysosomes are fused with the vacuole, the contents within the vacuole are digested by lysosomes' hydrolytic enzymes into the simpler subunits.
10: The centriole is made up of a ring of nine groups of microtubules. There are three fused microtubules in each group. The two centrioles are arranged such that one is perpendicular to the other. The centrioles can be found in most animal eukaryotic cells, but they are absent in higher plants and most fungi. During animal cell division, the centrosome divides and the centrioles replicate. The result is two centrosomes, each with its own pair of centrioles. The two centrosomes move to opposite ends of the nucleus, and from each centrosome, microtubules grow into a "spindle" which is responsible for separating replicated chromosomes into the two daughter cells. | Centrioles from common shore crab hepatopancreas | The centrioles are like straws. | Analogy:
11: Cilia and flagella are structures that aid in locomotion and help move fluids across the surface of tissue cells in animals. Cilia are relatively short structures that work like oars while flagella are relatively long structures that function as propellers in locomotion. Both cilia and flagella have a specialized arrangement of microtubules that are responsible for their locomotive ability. | Cilia are located all around the cell's body while flagella only grow on the tail part of most cells. | Cilia are like oars and flagella work as propellers. | Interaction between centrioles, cilia and flagella: Centrioles give rise to basal bodies that organizes the formation and direction of cilia and flagella.
12: Mitochondria are membrane-bound organelles, and like the nucleus have a double membrane. They provide the energy a cell needs to move, divide, produce secretory products, contract. The outer membrane is fairly smooth. But the inner membrane is highly convoluted, forming folds called cristae. The cristae greatly increase the inner membrane's surface area. It is on these cristae that food (sugar) is combined with oxygen to produce ATP - the primary energy source for the cell. Mitochondria are found exclusively in complex cells. | Two mitochondria from mammalian lung tissue displaying their matrix and membranes as shown by electron microscopy | Analogy: Mitochondria are like power plants in cells.
13: Chloroplasts capture light energy to conserve free energy in the form of ATP and reduce NADP to NADPH through a complex set of processes called photosynthesis. Chloroplasts are green because they contain the pigment chlorophyll. Chloroplasts are found in plant cells and other eukaryotic organisms that conduct photosynthesis. | The simplified internal structure of a chloroplast | Analogy: Chloroplasts are like solar power plants in cells. | Interaction between mitochondria and chloroplasts: Chloroplasts converts sunlight into energy with the help of the mitochondria.
14: The nucleus is the most obvious organelle in any eukaryotic cell. It is a membrane-bound organelle and is surrounded by a double membrane. It communicates with the surrounding cytosol via numerous nuclear pores. | A mouse fibroblast nucleus in which DNA is stained blue. The distinct chromosome territories of chromosome 2 (red) and chromosome 9 (green) are visible stained with fluorescent in situ hybridization | An electron micrograph of a cell nucleus, showing the darkly stained nucleolus | The nuclei are only found in the eukaryotic cells. The nucleus is like the CPU in a cell.
15: The ribosome builds proteins according to mRNA instructions. Ribosomes "read" the mRNA code and enlist other molecules to build the called-for protein from a store of amino acids free floating outside the nucleus. The ribosome links the corresponding amino acids together into a protein chain. The ribosomes can be found anywhere within the cytoplasm of a cell or attached to endoplasmic reticulum. The ribosome is like the a copying machine in a cell. | Interaction between the nucleus and the ribosome: The nucleus tells the ribosome what to do and the ribosome produces things according to the instruction.
16: The nucleolus is a non-membrane bound structure composed of proteins and nucleic acids. The nucleolus produces ribosomes, which move out of the nucleus to positions on the rough endoplasmic reticulum where they are critical in protein synthesis. The nucleolus is in the nucleus. The nucleolus is like a copy machine manufacturer | Interaction between the nucleolus and the ribosome: The nucleolus makes rRNA which helps in the production of ribosomes and ribosomes make proteins.
17: References: 1. http://wiki.answers.com/Q/How_do_lysosomes_and_vacuoles_work_together 2. http://wiki.answers.com/Q/What_is_a_Cell_membrane 3. http://www.nsf.gov/news/overviews/biology/interact01.jsp 4. http://en.wikipedia.org/wiki/Cell_wall 5. http://en.wikipedia.org/wiki/Cytoplasm 6. http://answers.ask.com/Science/Biology/what_is_the_job_of_a_cytoplasm 7. http://answers.yahoo.com/question/index?qid=20091108090700AAxKLiE 8. http://www.cellsalive.com/cells/cytoskel.htm 9. http://publications.nigms.nih.gov/insidethecell/chapter1.html 10. http://answers.yahoo.com/question/index?qid=20081011120527AAmihro 11. http://en.wikipedia.org/wiki/Cell_membrane 12. http://en.wikipedia.org/wiki/Nucleolus 13. http://www.cellsalive.com/cells/nucleus.htm 14. http://www.enotes.com/science/q-and-a/what-other-organelles-does-nucleolus- work-with-279102 15. http://en.wikipedia.org/wiki/Endoplasmic_reticulum 16. http://www.cellsalive.com/cells/golgi.htm 17. http://en.wikipedia.org/wiki/Golgi_apparatus 18. http://www.cellsalive.com/cells/vacuole.htm 19. http://en.wikipedia.org/wiki/Vacuole 20. http://www.cellsalive.com/cells/lysosome.htm 21. http://en.wikipedia.org/wiki/Centriole 22. http://www.northland.cc.mn.us/biology/biology1111/animations/flagellum.html 23. http://answers.yahoo.com/question/index?qid=20090129005835AAHlBcn 24. http://wiki.answers.com/Q/How_does_centrioles_and_cilia_work_together 25. http://www.cellsalive.com/cells/mitochon.htm 26. http://en.wikipedia.org/wiki/Chloroplast 27. http://wiki.answers.com/Q/How_do_chloroplast_and_mitochondria_interact_w ith_each_other