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Chapter 5

Chapter 5. Cell Structure and Function. 5-1 The Cell Theory. How did van leeuwenhoek, Hooke, Schleiden, Schwann, and Virchow contribute to the development of the cell theory? What are the parts of the cell theory?. All Living things are made of cells!.

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Chapter 5

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  1. Chapter 5 Cell Structure and Function

  2. 5-1 The Cell Theory • How did van leeuwenhoek, Hooke, Schleiden, Schwann, and Virchow contribute to the development of the cell theory? • What are the parts of the cell theory?

  3. All Living things are made of cells! • Cell- the basic unit of structure and function in living things • First found under lenses in microscopes • Lets talk about how

  4. History of the cell • First lenses were used in Europe hundreds of years ago for cloth quality. • They then combined lenses together to see better. http://www.bombayharbor.com/company/62262/product.html

  5. In 1600’s two important inventions! • What were they? • The telescope – For far away • The Microscope – small objects in nature visible http://www.robinsdocksideshop.com/telescopes2.htm http://www.olympusmicro.com/primer/anatomy/introduction.html

  6. Anton van Leeuwenhoek (LAY-Vuhn-hook) • Person given credit for making the first microscope • Could see tiny organisms whose world was a drop of water • Observed them in pond water and then made drawings

  7. On to England with Robert Hooke • Used one of his microscopes to look at pieces of cork, wood, and stems • Noticed thousands of tiny chambers • Why did he call them cells? http://science-of-aging.healthaliciousness.com/timelines/hooke-history-cell-discovery.php

  8. Was he looking at living or non-living cells? • Why was it significant?

  9. The next 200 years • Scientists found they were not only in plants • 1833- Robert Brown observed that any cells had a dark structure near the center (What do we call this now)? http://www.helloquizzy.com/quizzy/results?quizzyid=936650768789608524&resultid=3

  10. Germany 1838- Matthias Schleiden says, “all plant were made of cells.” 1839- Theodor Schwann says, “all animals were made out of cells.” 1855- Rudolf Virchow “New cells could be produced from the division of old cells.” All of these discoveries created the Cell Theory

  11. The Cell Theory • Three parts: • 1. All living things are composed of cells • 2. Cells are the basic units of structure and function in living things • All cells come from preexisting cells • Cell theory video!

  12. Picture take from: http://pearsonprophoto.com/pictures-of-the-cell-theory

  13. 5-2 Cell Structure • What are the functions of the three basic structures of most cells? • How do prokaryotes and eukaryotes differ? • Cell Video!

  14. Most cells have three common structures • The Cell membrane- outer boundary of the cell • The Nucleus – control center • The Cytoplasm – material between the cell membrane and the nucleus

  15. Cell Membrane • Regulates what enters and leaves the cell. Also, aids in the protection and support of the cell. • Think Walls in House

  16. What process do you think takes place in the cell membrane? • Communicate with other cells • Take in food and water • And eliminate wastes • Many molecules make it up but the most important are lipids. • A lipid bilayer forms the cell membrane

  17. Cell Membrane

  18. Gives a flexible structure, strong barrier between the cell and its surroundings Most have proteins embedded in lipid bilayer. So many molecules that they call cell membrane mosaic Picture From: http://en.wikibooks.org/wiki/Structural_Biochemistry/Lipids/Lipid_Bilayer

  19. Cell Membrane Video Some proteins form channels or pumps which help move material Carbohydrates act as chemical I.D. cards, it allows individual cells to identify each other. Picture From: http://php.med.unsw.edu.au/cellbiology/index.php?title=Cell_Membranes_and_Compartments

  20. Cell Wall • Cell Wall-Strong supporting layer around the cell membrane in plants, algae, and some bacteria • Lie outside the cell membrane • Allows water, oxygen, and carbon dioxide to pass through pretty easily. • Why is that important???

  21. Primary Cell Wall-cellulose (elasticity) • Secondary Cell Wall-Cellulose and lignin (Wood) Picture from: http://library.thinkquest.org/C004535/cell_wall.html

  22. Nucleus • Nucleus- structure that contains the cell’s genetic material (DNA) and controls the cell’s activities • Eukaryotes-organisms whose cells contain nuclei • Prokaryotes-organisms whose cells lack nuclei • It’s Greek “pro” = before “eu” = true • Prokaryotes evolved before the nucleus

  23. Nucleus Picture from: http://en.wikipedia.org/wiki/Cell_nucleus • Control center of the cell. • What does the nucleus contain? • DNA • What membrane surrounds the nucleus? • Nuclear envelope • Nuclear envelope-layer of two membranes that surrounds the nucleus of a cell

  24. What does the nuclear envelope do? • Allows material to move in and out of nucleus • Nucleolus-small, dense region within most nuclei in which ribosomes are made. • Ribosomes aid in the production of proteins

  25. Chromosomes • What is a chromosome and what does it form from? • Threadlike structure within the nucleus containing the genetic information that is passed from one generation of cells to the next. Forms from chromatin • What do chromosomes contain? • Genetic material

  26. Cytoplasm • Can divide the Eukaryotic cell into two major parts: Nucleus and cytoplasm • Cytoplasm-material inside the cell membrane-not including the nucleus • These two structures work together to create life picture from: http://www.stephsnature.com/lifescience/cytoplasm.htm

  27. 5-3 Cytoplasmic organelles • The structures in the cytoplasm are called organelles • Organelles-a tiny structure that performs a specialized function in the cell • Each has a special job that helps maintain the cell’s life

  28. Picture from: http://dbscience5.wikispaces.com/Bas

  29. Mitochondria and chloroplasts Power Stations • All living things require energy. Where do we get these from? • Sun or food substances • The mitochondrion and the chloroplast are the key organelles that change energy from one form to another.

  30. Mitochondria-change the chemical energy stored in food into compounds that the cell can use • Chloroplasts-trap the energy of sunlight and convert it into chemical energy. • What organisms are chloroplasts found in?

  31. Picture from: http://biology.about.com/od/cellanatomy/ss/mitochondria.htm Power House of the Cell!!!!!!!!!!!!! Picture from: http://en.wikipedia.org/wiki/Chloroplast

  32. Ribosomes: Protein Factories • Ribosomes-are the structures in which proteins are made • Cells are crowded with them if they are creating proteins • They are some of the smallest organelles 25 nanometers (1 billionth of a meter

  33. Ribosomes Picture from: http://en.wikipedia.org/wiki/Ribosome

  34. Endoplasmic Reticulum and Golgi Apparatus: Manufactures and Shippers • Endoplasmic Reticulum (ER)-transports materials through the inside of the cell • Two types: Smooth and Rough ER • Smooth ER-the walls and sacs look smooth. Enzymes and chemicals are stored here

  35. The Rough ER is covered with ribosomes. Why is that? • It is responsible for the synthesis of proteins • The Rough ER modifies newly made proteins Picture from: http://micro.magnet.fsu.edu/cells/endoplasmicreticulum/endoplasmicreticulum.html

  36. Golgi apparatus-proteins are moved here after the ER to be modified and then sent out of the cell • It looks like a flattened stack of pancakes Picture from:http://en.wikipedia.org/wiki/Golgi_apparatus

  37. Lysosomes: Cleanup Crews • A cell can encircle a particle and bring it into the cell called endocytosis • The particle must now be digested or broken down by the lysosomes • Lysosomes-structures that contain chemicals and enzymes necessary for digestion in the cell

  38. Lysosomes also break down organelles that have outlived their usefulness • Lysosomes are made by the Golgi apparatus Picture from: http://marionkatiemaggie.blogspot.com/2010/09/lysosomes.html

  39. Vacuoles and Plastids: Storage Tanks • Vacuoles-saclike structure that store materials such as water, salts, proteins, and carbs • Plants have large central vacuoles filled with water • Why is this important for cells?

  40. Picture From: http://en.wikipedia.org/wiki/Vacuole

  41. Plastids-plant organelles that may take many forms, one of which is the chlorplast • Many are involved in the storage of food and pigments. Example: chromoplasts which store pigments molecules. • Chromoplasts = red pigment in tomatoes

  42. Cytoskeleton: Framework • Cytoskeleton-composed of a variety of filaments and fibers that support the cell structure and drive the cell movement

  43. proteins that make up the cytoskeleton: • Microfilaments and microtubules • What are microfilaments? • Threadlike structures made of a protein called actin • What do these help cells do? • Can help cells move. Ex. amoebas

  44. What are microtubules? • Hollow structures made up of proteins known as tubulins • What critical role do they play? • Maintaining cell shape • What are centrioles? • Located near the nucleus and help organize cell division (Not in Plant cells) • What do microtubules help build and what do these structures help the cell to do? • Flagella and Cilia. Help cells swim through liquid

  45. 5-4 Movement of Materials Through the Cell Membrane • How do diffusion and osmosis move materials into and out of cells? • How do active and passive transport differ from each other? • What are endocytosis, phagocytosis, pinocytosis, and exocytosis?

  46. Each individual cell is covered in liquid that was once part of blood (in us that is). • This liquid allows food, oxygen, and water to move into and out of the cell • Several ways in which materials enter and leave the cell

  47. Diffusion through cell boundaries One main function of the membrane: to regulate the movement of dissolved molecules from the liquid on one side to the liquid on the other side of the membrane.

  48. Diffusion Picture from: http://en.wikipedia.org/wiki/Diffusion Particles are always moving in solution Diffusion-process by which molecules tend to move from an area where they are more concentrated to an area where they are less concentrated. Equilibrium- when a concentration of a solute is the same throughout the solution

  49. What does this have to do with cell membrane? If a substance is higher on one side of the cell membrane, and it is able to move through the membrane. It will move from the side with a higher concentration to the side with a lower concentration. Diffusion animation

  50. Picture from: http://good50x70.org/2007/gallery/gallery02/ Because diffusion depends upon random particle movements, substances diffuse across membranes Without requiring the cell to use energy! Even at equilibrium particles still move. Almost equal numbers of particles move in each direction, causes no further change in concentration

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