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Cell Theory and Cell Basics 2014

  1. Cell Theory 1
  2. Cell Theory This theory is one of the foundations of biology. 2
  3. Antonie van Leeuwenhoek The first man to witness a live cell under a microscope was Antonie van Leeuwenhoek, who in 1674 described the algae Spirogyra and named the moving organisms animalcules, meaning “little animals.” In 1678, Antoni van Leeuwenhook reported that he had observed “little animals” -- protozoa -- through a microscope, he also called them “little beasties.” 3
  4. Robert Hooke The cell was first discovered by Robert Hooke in 1665. He observed dead cork (cork comes from the bark of a cork oak0 tree) and named the structures he observed “cells” which means small room. 4
  5. Theodor Schwann Matthias Jakob Schleiden Rudolf Virchow In 1839, Schwann and Schleiden suggested that cells were the basic unit of life. In 1858, Rudolf Virchow concluded that all cells come from pre-existing cells, thus completing the classical cell theory. Theodor Schwann, Matthias Jakob Schleiden, and Rudolf Virchow are credited with developing cell theory. 5 Schwann Schleiden Virchow
  6. Traditional rules of the Cell Theory 1. All life forms are made from one or more cells. 2. Cells only arise from pre-existing cells. 3. The cell is the smallest form of life. 6
  7. Modern rules of the Cell Theory — 1 1 All known living things are made up of cells. All organisms are made up of one or more cells. 2 The cell is structural & functional unit of all living things. 3 All cells come from pre-existing cells by division. (Spontaneous Generation does not occur). 7
  8. Modern rules of the Cell Theory — 2 4 Cells contains hereditary information (DNA) which is passed from cell to cell during cell division. 5 All cells are basically the same in chemical composition. 6 All energy flow (metabolism & biochemistry) of life occurs within cells. 8
  9. Characteristics of Life Living? Homeostasis Organization Metabolism Growth Adaptation Response to stimuli Reproduce Hereditary molecule is DNA Viruses  Bacteria are living organisms but opinions vary on whether viruses are.  A virus is an organic structures that interacts with living organisms.  It does show characteristics of life such as having genes, evolving by natural selection and reproducing by creating multiple copies of themselves through self-assembly.  But viruses don't have a cellular structure or their own metabolism; they need a host cell to reproduce. 9
  10.  Viruses are the smallest and simplest life form known. They are 10 to 100 times smaller than bacteria. Viruses  Viruses must have a living host - like a plant or animal - to multiply.  Viruses are intracellular organisms (they infiltrate the host cell and live inside the cell). They change the host cell's genetic material from its normal function to producing the virus itself. 10
  11. Two basic cell types Prokaryotes & Eukaryotes 11
  12. Two basic cell types Prokaryotes & Eukaryotes 12
  13. PPrrookkaarryyootteess The lack of a nucleus gives prokaryotes their name.
  14. PPrrookkaarryyootteess  The prokaryotes are a group of organisms that lack a cell nucleus, or any other membrane-bound organelles.  They differ from the eukaryotes, which have a cell nucleus.  Most are unicellular, but a few prokaryotes such as myxobacteria have multicellular stages in their life cycles. 14
  15. Prokaryotes  The prokaryotes are divided into two domains: the bacteria and the archaea.  Archaea were recognized as a domain of life in 1990.  These organisms were originally thought to live only in inhospitable conditions such as extremes of temperature, pH, and radiation but have since been found in all types of habitats. 15
  16. Eukaryotes The presence of a nucleus gives eukaryotes their name. Greek Meaning eu good, noble, true karyon nut, kernel
  17. Eukaryotic A eukaryotic is an organism whose cells contain complex structures inside the membranes. 17
  18.  The most important membrane-bound structure setting eukaryotic cells apart from prokaryotic cells is the nucleus, or nuclear envelope, within which the genetic material is carried.  Most eukaryotic cells also contain other membrane-bound organelles such as mitochondria, chloroplasts and the Golgi apparatus. 18 Eukaryotic
  19. Organelles Found only in eukaryotic cells 19
  20. Nucleus The “control center,” it maintain the integrity of these genes and to control the activities of the cell by regulating gene expression. 20
  21. Nucleolus 21 Function: Ribosomal RNA (rRNA) is transcribed and assembled within the nucleolus.
  22. Cell Membrane or Plasma Membrane 22 Function: It separates the interior of a cell from the outside environment. The cell membrane surrounds all cells and it is semi-permeable, controlling the movement of substances in and out of cells.
  23. Cell Wall 23  Provides these cells with structural support and protection, and also acts as a filtering mechanism. A major function of the cell wall is to act as a pressure vessel, preventing over-expansion when water enters the cell. They are found in plants, bacteria, fungi, algae, and some archaea.
  24. Ribosome  Make proteins from amino acids. 24
  25. Vesicle Membrane-enclosed sac that stores or transports substances within a cell. 25
  26. Rough Endoplasmic Reticulum (RER) Ribosome to bind to the RER and pass the new protein through the ER membrane. 26
  27. Smooth Endoplasmic Reticulum (SER)  Several metabolic processes, including synthesis of lipids and steroids, metabolism of carbohydrates, regulation of calcium concentration, drug detoxification, attachment of receptors on cell membrane proteins, and steroid metabolism. 27
  28. Golgi apparatus Processes and packages macromolecules, such as proteins and lipids, after their synthesis and before they make their way to their destination; it is particularly important in the processing of proteins for secretion 28
  29. Cytoskeleton  It is a dynamic structure that maintains cell shape, protects the cell, enables cellular motion (using structures such as flagella, cilia and lamellipodia), and plays important roles in both intracellular transport (the movement of vesicles and organelles, for example) and cellular division. 29
  30. Mitochondria  Generate most of the cell’s supply of adenosine triphosphate (ATP), used as a source of chemical energy. In addition to supplying cellular energy, they are involved in a range of other processes, such as signaling, cellular differentiation, cell death, as well as the control of the cell cycle and cell growth. 30
  31. Vacuole  The function and importance of vacuoles varies greatly according to the type of cell in which they are present, having much greater prominence in the cells of plants, fungi and certain protists than those of animals and bacteria. In general, the functions of the vacuole include:  Isolating materials that might be harmful or a threat to the cell  Containing waste products  Maintaining internal hydrostatic pressure or turgor within the cell  Maintaining an acidic internal pH  Containing small molecules  Exporting unwanted substances from the cell  Allows plants to support structures such as leaves and flowers due to the pressure of the central vacuole 31
  32. Cytoplasm  Are filled with liquid that is kept separate from the rest of the cytoplasm by biological membranes. The cytoplasm is the site where most cellular activities occur, such as many metabolic pathways like glycolysis, and processes such as cell division. 32
  33. Lysosome Lysosomes digest excess or worn-out organelles, food particles, and engulfed viruses or bacteria. 33
  34. Centrioles within Centrosome  These are involved in the organization of the mitotic spindle and in the completion of cytokinesis (the process in which the cytoplasm of a single eukaryotic cell is divided to form two daughter cells). 34
  35. Chloroplasts 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. 35
  36. Organelles PPllaannttss Cell Membrane Cell walls Chloroplasts Vacuoles  Lysosomes Golgi Bodies Mitochondria Endoplasmic Reticulum (ER) Ribosomes AAnniimmaallss Cell Membrane Centrioles (used in cellular reproduction) Vacuoles Lysosomes Golgi Bodies Mitochondria Endoplasmic Reticulum (ER) Ribosomes 36
  37. Cell Theory Rap Listen close to the story I tell. It’s the rapping story of the living cell. It’s a happy tune that’s sort of cheery. About a real tough topic called the cell theory. All animals, plants, and protists too, Are made of cells with different jobs to do. They’re the basic units of all organisms, And I hope by now you got the rhythm. 37
  38. It all started with one dude named Hooke. Who at some cork cells took a look. He used a scope and took his time. ‘Cause a cell is small and thinner than a dime. Say 1, 2, 3, 4, Are you ready to learn some more? The animal cell has many parts, And you must know each one by heart. 38
  39. Like the farmer man in the dell. The nucleus controls the cell. its gives the orders -- kind of like a brain. And it’s protected by a nuclear membrane. Around the cell, you’ll find another “skin,” The cellular membrane holds the whole cell in But its job isn’t simple there’s no doubt, It lets some particles go in and out. 39
  40. Now please don’t lose your science enthusiasm, Listen to the story of the cytoplasm. All around the cell this thick fluid does go, But in the nucleus it will not flow. And don’t forget those ribosomes - This is where proteins come from. These protein factories are so small, you’ll agree, You need an electron microscope to see. 40
  41. Just when you thought you weren’t having any fun, Along comes teh endoplasmic reticulum. These tubelike structures serve as a track, To carry stuff to the membrane and back. Now have you ever seen any doughnuts without holes? In a cell, they’re called vacuoles. They’re filled with stuff like H2O And they carry food so the cell can grow. 41
  42. Las of all, but not the very least, Mitochondria - mighty cellular beasts, Since they turn sugars into energy so well, We call them the powerhouse of the cell. Now my friend, you know it well, The unforgettable story of the living cell. “Science World” 10-5-90 42