Tour of the CellAP Biology                      2007-2008
Types of cells         Prokaryote                        bacteria cells           Eukaryote        Eukaryote         anima...
Why organelles?    Specialized structures                                 mitochondria            specialized functions ...
Cells gotta live!    What jobs do cells have to do?            building proteins              proteins control         ...
Why study protein production?                        proteins                                                 cellsDNA    ...
Building Proteins    Organelles involved         nucleus         ribosomes         endoplasmic reticulum          (ER)...
TO:    nucleus              endoplasmic                          reticulum                                                ...
Putting it together…                     Making proteins                nucleus         cell                 nuclear pore ...
Cells gotta live!    What jobs do cells have to do?            make proteins              proteins control             ...
Cells need power!     Making energy          take in food & digest it          take in oxygen (O )                     ...
1960 | 1974   Lysosomes                             Christian de Duve    Function            little “stomach” of the cel...
Lysosomal enzymes     Lysosomal enzymes work best at pH 5            organelle creates custom pH            how?       ...
But sometimes cells need to die…    Lysosomes can be used to kill cells when       they are supposed to be destroyed     ...
syndactyly   Fetal development6 weeks                                   15                                weeksAP Biology
When things go wrong…    Diseases of lysosomes are often fatal        digestive enzyme not working in lysosome        p...
From food to making Energy     Cells must convert incoming energy to        forms that they can use for work          mi...
Mitochondria & Chloroplasts    Important to see the similarities            transform energy              generate ATP ...
Membrane-bound Enzymes         glucose + oxygen → carbon + water + energy                            dioxideAP Biology    ...
Membrane-bound Enzymes   carbon + water + energy → glucose + oxygen   dioxide        6CO2 + 6H2O + light → C6H12O6 + 6O2AP...
Mitochondria are everywhere!!      animal cells        plant cellsAP Biology
Cells gotta live!    What jobs do cells have to do?            building proteins              proteins control         ...
Cytoskeleton     Function            structural support               maintains shape of cell               provides a...
Cytoskeleton                   actin                   microtubule                   nucleiAP Biology
Centrioles     Cell division          in animal cells, pair of centrioles           organize microtubules          guid...
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  • Why organelles? There are several reasons why cells evolved organelles. First, organelles can perform specialized functions. Second, membrane bound organelles can act as containers, separating parts of the cell from other parts of the cell. Third, the membranes of organelles can act as sites for chemical reactions. Organelles as specialized structures An example of the first type of organelle is cilia, these short filaments act as "paddles" to help some cells move. Organelles as Containers Nothing ever invented by man is as complex as a living cell. At any one time hundreds of incompatible chemical reactions may be occurring in a cell. If the cell contained a uniform mixture of all the chemicals it would not be able to survive. Organelles surrounded by membranes act as individual compartments for these chemical reactions. An example of the second type of organelle is the lysosome. This structure contains digestive enzymes, these enzymes if allowed to float free in the cell would kill it. Organelle membranes as sites for chemical reactions An example of the third type of organelle is the chloroplast. The molecules that conduct the light reactions of photosynthesis are found embedded in the membranes of the chloroplast.
  • lysosomes create a space where cell can digest macromolecules safely rupturing a few lysosomes has little impact on a cell (pH of cytosol affects functionality of the lysosomal enzymes), but massive leakage from lysosomes can destroy cell why evolve digestive enzymes which function at pH so different from cytosol? digestive enzymes won’t function well if leak into cytosol = most times don’t want to digest yourself! low pH = acid environment cause oxidation (removing electrons) & promotes hydrolysis
  • Feedback mechanism There are sensors in the cell that monitor growth. They trigger self-destruct when they sense processes. Brown spots on leaves too. Virus infected plant cell auto-destructs and even cells around it to wall off virus.
  • 26 ch05cellsoverview2007

    1. 1. Tour of the CellAP Biology 2007-2008
    2. 2. Types of cells Prokaryote bacteria cells Eukaryote Eukaryote animal cellsAP Biology plant cells
    3. 3. Why organelles?  Specialized structures mitochondria  specialized functions  cilia or flagella for locomotion  Containers  partition cell into compartments chloroplast  create different local environments  separate pH, or concentration of materials  distinct & incompatible functions  lysosome & its digestive enzymes Golgi  Membranes as sites for chemical reactions  unique combinations of lipids & proteins  embedded enzymes & reaction centers  chloroplasts & mitochondriaAP Biology ER
    4. 4. Cells gotta live!  What jobs do cells have to do?  building proteins  proteins control every cell function  make energy  for daily life  for growth  build more cells  growth  reproduction  repairAP Biology
    5. 5. Why study protein production? proteins cellsDNA Repeat after me… DNA gets the glory, butAP Biology organism Proteins do all the work!
    6. 6. Building Proteins  Organelles involved  nucleus  ribosomes  endoplasmic reticulum (ER)  Golgi apparatus  vesicles The Protein Assembly Line Golgi nucleus ribosome ER vesicles apparatusAP Biology
    7. 7. TO: nucleus endoplasmic reticulum protein on its way! TO:DNA RNA vesicle TO: TO: vesicle TO:ribosomes protein finished protein Golgi apparatus Making ProteinsAP Biology
    8. 8. Putting it together… Making proteins nucleus cell nuclear pore membrane protein secreted rough ER ribosome vesicle proteins smooth ER transport Golgi vesicle apparatusAP Biology cytoplasm
    9. 9. Cells gotta live!  What jobs do cells have to do?  make proteins  proteins control every cell function ATP  make energy  for daily life  for growth  build more cells  growth  reproduction  repairAP Biology
    10. 10. Cells need power!  Making energy  take in food & digest it  take in oxygen (O ) 2  make ATP  remove waste ATPAP Biology
    11. 11. 1960 | 1974 Lysosomes Christian de Duve  Function  little “stomach” of the cell  digests macromolecules  “clean up crew” of the cell  cleans up broken down organelles  Structure  vesicles of digestive enzymes Where old organelles go to die!AP Biology only in animal cells
    12. 12. Lysosomal enzymes  Lysosomal enzymes work best at pH 5  organelle creates custom pH  how?  proteins in lysosomal membrane pump H+ ions from the cytosol into lysosome  why?  enzymes are very sensitive to pH  why?  enzymes are proteins — pH affects structure  why is this an adaptation: digestive enzymes which function at pH different from cytosol?  digestive enzymes won’t function well if some leakAP Biology into cytosol = don’t want to digest yourself!
    13. 13. But sometimes cells need to die…  Lysosomes can be used to kill cells when they are supposed to be destroyed  some cells have to die for proper development in an organism  apoptosis  “auto-destruct” process  lysosomes break open & kill cell  ex: tadpole tail gets re-absorbed when it turns into a frog  ex: loss of webbing between your fingers during fetal development  ex: self-destruct of cancerous cellAP Biology
    14. 14. syndactyly Fetal development6 weeks 15 weeksAP Biology
    15. 15. When things go wrong…  Diseases of lysosomes are often fatal  digestive enzyme not working in lysosome  picks up biomolecules, but can’t digest one  lysosomes fill up with undigested material  grow larger & larger until disrupts cell & organ function  lysosomal storage diseases  more than 40 known diseases  example: Tay-Sachs disease build up undigested fatAP Biology in brain cells
    16. 16. From food to making Energy  Cells must convert incoming energy to forms that they can use for work  mitochondria: from glucose to ATP ATP  chloroplasts: from sunlight to ATP & carbohydrates  ATP = immediate energy  carbohydrates = stored energy ATP +AP Biology
    17. 17. Mitochondria & Chloroplasts  Important to see the similarities  transform energy  generate ATP Lynn Margulis U of M, Amherst  double membranes = 2 membranes  semi-autonomous organelles  move, change shape, divide  internal ribosomes, DNA & enzymesAP Biology
    18. 18. Membrane-bound Enzymes glucose + oxygen → carbon + water + energy dioxideAP Biology C6H12O6 + 6O2 → 6CO2 + 6H2O + ATP
    19. 19. Membrane-bound Enzymes carbon + water + energy → glucose + oxygen dioxide 6CO2 + 6H2O + light → C6H12O6 + 6O2AP Biology energy
    20. 20. Mitochondria are everywhere!! animal cells plant cellsAP Biology
    21. 21. Cells gotta live!  What jobs do cells have to do?  building proteins  proteins control every cell function  make energy  for daily life  for growth  build more cells  growth  reproduction  repairAP Biology
    22. 22. Cytoskeleton  Function  structural support  maintains shape of cell  provides anchorage for organelles  protein fibers  microfilaments, intermediate filaments, microtubules  motility  cell locomotion  cilia, flagella, etc.  regulation  organizes structures & activities of cellAP Biology
    23. 23. Cytoskeleton  actin  microtubule  nucleiAP Biology
    24. 24. Centrioles  Cell division  in animal cells, pair of centrioles organize microtubules  guide chromosomes in mitosisAP Biology

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