A&P Chapter 4.txt

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A&P Chapter 4.txt
2012-09-28 19:22:05
Physiology cell

Physiology of a cell
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  1. Passive Transport
    • Does not require energy to move thru a cell membrane
    • High concentration to low concentration
  2. Types of Passive Transport
    • Diffusion
    • Simple Diffusion
    • Osmosis
    • Facilitated Diffusion
  3. Diffusion
    • Molecules spread thru the membranes
    • Molecules move from an area of high concentration to an area of low concentration
    • Does not require a membrane
  4. Simple Diffusion
    • Small uncharged molecules cross through a phospholipid bilayer
    • This requires diffusion thru a membrane
  5. Osmosis
    • Diffusion of water through a selectively permeable membrane.
    • Water pressure develops as a result of osmosis and is called osmotic pressure
  6. What positive ion is extracellular?
  7. What positive ion is intracellular?
  8. What is the overall direction of osmosis towards?
    Towards the concentrated solution
  9. Potential osmotic pressure
    The maximum pressure that could develop in a solution when it is separated from pure water by selectively permeable membrane
  10. Isotonic
    When two fluids have the same potential osmotic pressure. Water moves in equal amounts in the same direction
  11. Hypertonic
    • “higher pressure”
    • Cells placed in solution that are hypertonic to intracellular fluid ALWAYS shrivel as water flows out of the cell (FROM LOW OSMOTIC PRESSURE TO HIGH OSMOTIC PRESSURE)
There are more solutes than water. More water is needed here, so water will be taken from the ever is put in the solution
  12. Hyoptonic
    • “lower pressure”
    • Cells placed in a hypotonic solution may swell as water flows into them.
    • There is more water in the solution. To even it out, water is going to enter the cell.
  13. Facilitated Diffusion
    • Movement of molecules is made more efficient by the action of transporters embedded in a cell membrane.
    • Proteins assist in the transportation of substances down a concentration gradient
  14. Catabolism
    Breaks large molecules into smaller ones to release energy
  15. What is an example of catabolism?
    Carbohydrate breakdown- breakdown glucose to get ATP to be stored in mitochondria.
  16. What are the pathways of cellular respiraton?
    • Glycolosis
    • Citric Acid Cycle
    • Electron Transport System
  17. Where does the electron transport system occur?
  18. Where does the Citric Acid Cycle Occur?
    In the mitochondria with use of oxygen
  19. Where does glycolosis occur?
    In the cytoplasm
  20. Cellular respiration
    The pathway in which glucose if broken down to yield its stored energy
  21. Anabolism
    Builds large molecules from smaller one. This normally consumes energy
  22. What is an example of anabolism?
    Protein manufacture- DNA
  23. Enzyme
    • Chemical catalysts that reduce the activation energy needed for a reaction
    • Regulates a cell meatabolism
  24. What regulates a cell metabolism?
  25. Channel mediated passive diffusion
    Channels are specific allowing only one type of solute to pass thru
  26. Aquaporins
    Water channels that permit rapid osmosis
  27. Active Transport
    • Require ATP
    • Transport by Pumps
    • Transport by Vesicles
  28. What are examples of pumps?
    • Calcium pump
    • Sodium- Potassium pump
  29. What are examples of transport by vesicles?
    • Endocytosis
    • Exocytosis
  30. Transport by vesicle
    Allows substances to enter or leave the interior of the cell without actually moving through its plasma membrane
  31. Transport by pump
    Move substance against a concentration gradient from low concentration to high concentration
  32. Endocytosis
    The plasma membrane traps some extracellular material and brings it into the cell in a vesicle
  33. Two types of Endocytosis
    • Phagocytosis
    • Pinocytosis
  34. Phagocytosis
    • Condition of cell eating
    • Once in the cell the vesicle fuses with a lysosome
  35. Pinocytosis
    Condition of cell drinking
  36. Recepetor mediated endocytosis
    Membrane receptor molecules recognizes substance to be brought into cell
  37. Exocytosis
    Process in which large molecules, mostly proteins, can leave the cell even they are too large to pass thru the plasma membrane
  38. What provides for a way for new material to be added to the plasma membrane?
  39. What are the general functions of enzymes?
    Enzymes regulate cell functions by regulating metabolic pathways
  40. What are some examples of allosteric effectors?
    • Temp
    • Hydrogen Ions
    • Ionizing radiation
    • Cofactors
  41. What do allosteric effectors do?
    They change the shape of the enzyme molecule activation site
  42. Explain the metabolic pathway regulated by enzymes
    The product of one enzyme-regulated reaction becomes the substrate for the next reaction. Thus, a whole series of enzymes is required to keep the pathway functioning.
  43. What are many enzymes synthesized as?
    Inactive proenzymes
  44. Can enzymes catalyze in both directions?
  45. DNA
    A double-helix polymer that functions to transfer information, encoded in genes, that directs the synthesis of proteins
  46. Gene
    A segment of DNA molecule that consists of aprx 1000 pairs of nucleotides and they determine the cell structure and function
  47. Mitosis
    Cell division that occurs in all body cells where the daughter cells have the same number of chromosomes as the mother cells
  48. Meiosis
    • Cell division where the daughter cells have half the number of cells as the mother cells.
  49. Cell growth
    Depends on using genetic information in DNA to make the structural and functional proteins needed for cell survival
  50. Cell reproduction
    Ensures that genetic information is passed from one generation to the next
  51. Cytokinesis
    Division of cytoplasm