BIO 370 E3 C8 ER

  1. Membranes divide the cytoplasm of eukaryotic cells into WHAT 2 ITEMS
    distinct compartments and interconnected networks of canals
  2. T OR F?
    Membrane-bound structures of various diameter containing material of different electron density are found in all eukaryotic cells
    TRUE
  3. DEFINE Endomembrane system
    • ANYTHING THAT HAS TO DO WITH THE INSIDE OF THE CELL AND THE MEMBRANE.
    • Biosynthetic pathways
    • Secretory pathways
    • Endocytic pathways move materials into cells
    • Sorting signals
  4. DEFINE EXOCYTOSIS/ENDOCYTOSIS
    • EXOCYTOSIS...OUT OF CELL..OUT CYTO
    • ENDOCYTOSIS..INTO CELL...IN CYTO
  5. 1974 Nobel Prize for 3 cell biologists: Study of Cytomembranes
    • De Duve (University of Louvain in Belgium),
    • Claude &
    • Palade (both of Rockefeller University)
  6. James Jamieson & George Palade - worked with WHAT?
    • pancreas acinar cells; followed secretory protein from synthesis to secretion & determined individual steps even though all of them occurred simultaneously.
    • PULSE/CHASE METHOD
  7. __________ ________cells have a particularly extensive endomembrane system; ideal for study by autoradiography
    • Pancreas acinar
    • METHOD KNOWN AS PULSE/CHASE METHOD.
  8. WHAT PROCESS ALLOWS ONE TO OBSERVE BIOCHEMICAL PROCESS?
    Autoradiogram...PULSE/CHASE
  9. NAME A HOT/COLD AMINO ACID.
    • HOT....SULFER35..PULSE..DISULFIDE BRIDGES
    • COLD...REGULAR SULFER
  10. WHAT IS THE 1ST STEP IN AUTORADIOGRAPHY?
    Incubate tissue with hot amino acids briefly —> incorporated into digestive enzymes as they are made on ribosomes...S35 GOES FOR DISULFIDE BRIDGES.
  11. IN PALADE & JAMIESON'S PULSE/CHASE METHOD, WHAT ARE THE HOT(PULSE) & COLD (CHASE)?
    AMINO ACIDS
  12. T OR F ?
    IN AUDIORADIOGRAPHY....The longer the chase, the farther the hot (radioactive) proteins made during the pulse will have traveled from their synthesis site (the RER) within the cell
    • TRUE
    • BECAUSE, unlabeled amino acids (chase), which lasts for varying time periods, protein synthesis continues using nonradioactive amino acids
  13. THE SECRETORY PATHWAY IS ALSO KNOW AS WHAT?
    BIOSYNTHETIC PATHWAY
  14. HOW WOULD YOU USE A VIRUS AND GFP?
    • vesicular stomatitis virus gene (VSVG) is fused to GFP gene; viruses useful since they turn cells into factory for producing one or a few viral proteins.
    • Cell begins to make massive amounts of VSVG protein in RER
  15. DEFINE temperature-sensitive mutants
    • Mutants of this type that function normally at reduced (permissive) temperature, but not at elevated (restrictive).
    • CONTROL TEMP, CONTROL MOVEMENT.
    • DOESN'T GO IN REVERSE.
  16. THE vesicular stomatitis virus gene (VSVG) REACTIONS TO TEMPERATURE: 40C & 32C
    • 40C: GROWS, BUT DOESNT LEAVE ER
    • 32C: LEAVES ER & GOES TO GOLGI AND SO ON.

    • VSVG IS KNOWN AS temperature-sensitive mutant.
    • Image Upload 2
  17. Cell homogenization & organelle isolation (CELL FRACTIONAL) techniques were pioneered by WHO & WHEN?
    Claude & De Duve (1950s & 1960s)
  18. Purification of subcellular fractions by density gradient equalibrium centrifugation. (SUCROSE) LYSOSMES, MITOCHONDRIA & PEROXISOMES.
    WHERE DOES EACH FALL?
    • 65,000g @ 2HRS
    • Image Upload 4
  19. Vesicles from different parts of Golgi were found to have enzymes that add different sugars to the ends of growing ____ chains of ________ & _________.
    • CHO
    • glycoprotein or glycolipids
  20. EXAMPLE OF glycolipids
    SUGARS THAT MAKE ANTIGENS OF RBC
  21. Vesicles from different parts of Golgi were found to have enzymes that add different sugars to the ends of growing CHO chains of glycoprotein or glycolipids.
    HOW CAN ONE USE THIS INFO IN ORDER TO USE GOLD AS A TAG TO STUDY GOLGI?
    • Purify these enzymes from the microsomal fraction; use them as antigens to make antibodies & attach gold particles to the antibodies, locations of which in Golgi membranes can be seen in EM.
    • Revealed role of Golgi complex in stepwise assembly of complex carbohydrates
  22. studied properties of rough microsomal fraction (cell-free systems, isolated parts of cell)...WHO & WHEN?
    Palade & Siekevitz, et al. (Rockefeller University, 1960s)
  23. DEFINE Cell-free liposomes
    vesicles whose walls consist of an artificial bilayer created from purified phospholipids, used to study specific roles of proteins involved in budding
  24. T OR F?
    Mammalian (EUKARYOTIC) cell-free systems can use yeast proteins to facilitate vesicle transport.
    • TRUE.
    • can "cure" yeast biosynthetic pathway mutants by genetically engineering them to carry normal mammalian genes
  25. Membranes of the ER enclose a ______ space (cisternae)
    lumenal
  26. An interconnecting network of tubular membranes elements
    Smooth ER (SER)
  27. Functions include:
    Synthesis of steroids in endocrine cells gonads and adenal cortex
    Detoxification of organic compounds in liver via oxygenases: occasional faulty carcinogen conversion
    WHAT THE HELL IS IT?
    SMOOTH ER (SER)
  28. Sequestration of Ca+ in sarcoplamic reticulum (MUSCLE)... WHAT ORGANELLE OF THE CELL DOES THIS?
    SMOOTH ER (SER)
  29. ___________ oxydizes thousands of hydrophobic compounds- convert them to more hydrophylic/excretable
    Cytochome p450
  30. Proteins synthesized on ribosomes of RER
    • Secretory,
    • integral membrane,
    • proteins of organelles
  31. Proteins synthesized on “free” ribosomes.
    • Cytosolic proteins,
    • peripheral membrane proteins,
    • nuclear proteins
    • chloroplast and mitochondrial proteins
  32. WHAT SIDE ARE THE RIBSOMES ON IN THE RER?
    ribosomes on the cytosolic side of continuous flattened sacs (cisternae).

    FACES OUT INTO THE CELL, NOT TOWARDS NECLEUS.
  33. WHERE IN THE FUCK DO YOU FIND MUCOPROTEINS?
    • Mucous secreting goblet cell from a rat colon. ER products move to golgi and are packaged in membrane as concentrated mucoproteins.
    • Image Upload 6
  34. 5 STEPS TO SIGNAL SEQUENCE ON MEMBRANE BOUND RIBOSOME ON RER.
    • 1. Signal sequence binds a signal recognition particle (SRP)
    • 2. Then attaches to an SRP receptor on the ER membrane 3. SRP and SRP receptor must both bind to GTP in order to interact (G proteins)
    • 4. Sequence is being moved through membrane as it is being synthesized i.e. a co-translational event
    • 5. Protein conducting channel is blocked by chaperone protein on lumenal side of the ER
  35. HOW DO YOU MAKE NON-MEMBRANE ASSOCIATED PROTEIN. (secretory protein, lysosomal enzyme, hormone)
    Image Upload 8
  36. In the Model of synthesis of secretory protein (or lysosomal enzyme) on membrane-bound ribosome of RER, name the chaperone.
    • BiP
    • Image Upload 10
  37. WHAT THE HELL IS A TRANSLOCON CHANEL?
    • ITS IN THE ER MEMBRANE
    • Image Upload 12
  38. synthesis of secretory protein...2 TYPES OF RNA ARE INVOLVED. WHAT/WHERE ARE THEY?
    • Messenger RNA binds to free ribosomes in the cytosol.
    • Image Upload 14
  39. DEFINE nascent protein
    A protein as it is being formed by a ribosome before it folds into its active shape.
  40. synthesis of integral membrane protein..NAME THE 6 STEPS
    Image Upload 16
  41. synthesis of integral membrane protein.. THE STOP TRANSFER SEQUENCE...HYDROPHOBIC OR HYDROPHILLIC....WHY?
    • HYDROPHOBIC.
    • IT'S INTERGRAL, GOING THRU BILAYER. CANT BE HYDROPHILLIC OR IT WOULD WANT TO LEAVE THE CELL.
  42. WHAT IS THE PURPOSE OF A CHAPERON IN THE SYNTHESIS OF INTEGRAL MEMBRANE PROTEIN?
    • chaperone protein must block the open channel (TRANSLOCON) on the luminal side and act as a permeability barrier.
    • Image Upload 18
  43. T OR F ?
    Maintenance of membrane asymmetry...This orientation doesn’t change as it moves from ER-GC-PM.
    • TRUE.
    • Image Upload 20
  44. TO MAINTAIN THE MEMBRANE ASYMMETRY WHEN A MEMBRANE IS PRODUCED AND CARBS ADDED ON PROVIDE INFO ON SIDENESS OF PROTEINS, WHAT SIDE?
    cisternal (OUTSIDE) side of vesicle material.This becomes the exoplasmic side for plasma membrane destined proteins post fusion.
  45. __________ transfer proteins that move lipids between membranes
    Phospholipid
  46. Lipids are inserted into the outer leaflet of ER and are modified by WHAT? NAME 4
    • FLIPASE
    • Conversion of one type phospholipid to another
    • Selective inclusion in new vesicles
    • Phospholipid transfer proteins that move lipids between membranes
  47. T OR F?
    Modifying the lipid composition of membranes AS THE MEMBRANE TRAVELS THRU ER GC PM EITHER START HIGH AND GO LOW OR START LOW AND GO HIGH.
    • TRUE
    • Image Upload 22
  48. This is site of synthesis for proteins destined for secretion, lysosomes, or membranes.
    The endoplasmic reticulum (ER)
  49. The site of lipid and steroid synthesis. New membrane is made here.
    smooth er
  50. DEFINE CISTERNAL SIDE.
    • THE OUTER SIDE. LUMEN IS INSIDE.
    • Image Upload 24
  51. INTEGRAL PROTEIN SYMETRY
    LIPIDS
    HORMONES
    WHERE ARE THEY PRODUCED?
    SMOOTH ER
  52. NAME 3 PHOSPHOLIPIDS
    • PHOSPHATIDYLCHORLINE
    • PHOSPHATIDYLERSINE
    • SPHINGOMYELIN
  53. Three mechanisms for changing phospholipids (PL) between ER-GC-PM...NAME THEM
    • 1) head groups are modified enzymatically
    • 2) Membrane forming vesicle contains different PL composition than what it buds from
    • 3) Pl can be removed from one membrane and inserted into another via PL-transfer proteins.
    • Image Upload 26
  54. WHAT THE HELL IS THIS?
    Image Upload 28
    • Three mechanisms for changing phospholipids (PL) between ER-GC-PM.
    • 1) head groups are modified enzymatically
    • 2) Membrane forming vesicle contains different PL composition than what it buds from
    • 3) Pl can be removed from one membrane and inserted into another via PL-transfer proteins
  55. _________ add carbohydrates to almost all proteins produced by membrane bound ribosomes (glycoproteins)
    Glycosyltransferases
  56. WHERE DOES Glycosylation OCCUR? WHAT IS IT?
    OCCURS IN THE RER. ITS WHEN YOU ADD CARBOHYDRATES TO PROTEINS PRODUCED MY MEMBRANE BOUND RIBSOMES (GLYCOPROTEINS)
  57. DURING Glycosylation in the RER, Glycosyltransferases add carbohydrates to almost all proteins produced by membrane bound ribosomes (glycoproteins). Sugars are attached in a ordered sequence.The core carbohydrate chain is assembled on a lipid carrier. WHAT IS THE CARRIER?
    Dolichol phosphate
  58. Dolichol phosphate...WHERE IS IT FOUND AND WHATS IT FUNCTION?
    Glycosylation in the RER. IT IS A LIPID CARRIER THE THE CORE CARBOHYDRATE CHAIN IS ASSEMBLED UPON.
  59. DURING Glycosylation in the RER, the core carbohydrate chain is assembled on a lipid carrier, Dolichol phosphate.

    WHAT HAPPENS NEXT?
    • The core carbohydrate is transferred to the polypeptide by oligosaccharyltransferase. It is modified en route to the Golgi complex.
    • (OLIGO MEANS SHORT.)
  60. SUGARS DON'T LIKE MEMBRANE WHY?
    THEY CONATIN ALOT OF ALCOHOL GROUPS ON THEM.
  61. Steps in synthesis of core portion of N-linked oligosaccharides in RER.
    Image Upload 30
  62. After Glycosylation in the RER what are the 2 steps to vesicular transport protein/sugar product from the lumen of the RER to the GC?
    • Membranes and luminal proteins move to the tips of the RER.
    • Transitional elements (ie, RER tips) form the first transport vesicles.
    • THEN OFF TO THE GC
  63. Cytoplasmic membrane systems are characteristic of what types of cells?
    A. prokaryotic cells
    B. eukaryotic cells
    C. bacterial cells
    D. all cells
    eukaryotic cells
  64. Pancreatic cells that produce and release digestive enzymes engage in what type of secretion?
    A. regulated secretion
    B. constitutive secretion
    C. transport secretion
    D. none of the above
    regulated secretion
  65. Which of the following cell types would be the best model system for studying secretory granules?
    A. muscle cells
    B. yeast cells
    C. epithelial cells
    D. pancreatic cells
    pancreatic cells
  66. You are interested in studying the asymmetric (coming from just one cell side) release of digestive enzymes from epithelial cells that line the digestive tract. Which of the following techniques would be best for these studies?
    A. cell fractionation
    B. homogenization
    C. autoradiography
    D. all of the above
    autoradiography
  67. why microsomes can't be seen in cells viewed with the electron microscope?
    They are artifacts of homogenization and centrifugation.

    **THIS IS FROM THE ONLINE QUIZ AND YES THIS WAS THE CORRECT ANSWER**
  68. Which of the following proteins would not be found in the smooth endoplasmic reticulum?
    A. Ca2+-pumping enzymes
    B. cytochrome P450
    C. glucose 6-phosphatase
    D. signal peptidase
    signal peptidase
  69. Which of the following groups of proteins probably lack a signal sequence?
    A. acid hydrolase enzymes synthesized in macrophage cells B. glycolytic enzymes synthesized in liver cells
    C. polypeptide hormones synthesized in endocrine cells
    D. antibody hormones synthesized in plasma cells
    glycolytic enzymes synthesized in liver cells
  70. Which of the following is not an essential component of the complex that directs a nascent protein into the lumen of the RER?
    A. protein disulfide isomerase
    B. SRP
    C. SRP receptor
    D. GTP-binding protein
    SRP

    *****THIS IS FROM THE ONLINE QUIZ AND YESTHIS WAS THE ANSWER*******
  71. WHEN A PROTEIN, INTEGRAL OR SECRETORY, GETS MISFOLDED WHERE IS IT DESTROYED?
    CYTOSOL. UBIQUEIN ATTACHES AT LYSOSOMES ATTACK IT.
  72. If you compared the proteins in a cis Golgi compartment with those in a trans Golgi compartment, you would find WHAT?
    the proteins in the cis compartment are glycosylated, whereas those in the trans compartment are glycosylated and contain modified amino acids
  73. You are tracing the path of a secretory protein from its synthesis to its export from a cell. RADIOACTIVE TAGED. List the order in which the proteins of these fractions first exhibit radioactivity.
    I secretory vesicles
    II Golgi complex
    III rough ER
    IV smooth ER
    V nucleus
    III--->II---->I---->out of the cell
  74. Of the following processes that occur during protein trafficking, which involve GTP?
    A. protein translocation across the ER membrane
    B. disassembly of the COP coat on a transport vesicle
    C. fusion of non-clathrin coated vesicles with target membrane
    D. all of the above
    ALL THE ABOVE
  75. You have labeled the lipids on a patch of rough ER membrane with a fluorescent probe. After a few minutes, the probe shows up in the membranes of the cis Golgi. Now you treat the cells with the drug brefeldin A. Where might the fluorescent probe show up next?
    A. trans Golgi network
    B. endoplasmic reticulum
    C. plasma membrane
    D. secretory vesicles
    endoplasmic reticulum

    ANOTHER ONE FROM THE ONELINE TEST
  76. v-SNARE proteins are to transport vesicles as KDEL sequences are to ? .
    A. t-SNARE proteins
    B. escaped ER proteins
    C. ERGIC vesicles
    D. coat proteins
    t-SNARE proteins
  77. Which type of vesicle of the trans Golgi network would be most likely to carry hormones destined for regulated secretion?
    A. lysosomal vesicles
    B. clathrin-coated vesicles
    C. non-clathrin-coated vesicles
    D. all of the above
    clathrin-coated vesicles
  78. COPII-coated vesicles are to anterograde movement as ______ are to retrograde movement.
    COPI COATED VESICLES
  79. Of the following, which would be least likely to be found in lysosomes?
    A. acid hydrolase enzymes
    B. a half-digested mitochondrion
    C. nucleic acids
    D. a high concentration of protons
    nucleic acids
  80. Uptake of low-density lipoproteins (LDL) occurs by _____, whereas retrieval of plasma membrane after extensive secretory activity occurs by ________.
    receptor-mediated endocytosis, bulk-phase endocytosis
  81. Which of the following are not associated with coated pits? A. TGN
    B. triskelion
    C. adaptor complexes
    D. integral membrane receptors
    TGN
  82. Which cells of the body would probably be the richest in HDL receptors?
    A. stomach cells
    B. liver cells
    C. muscle cells
    D. epithelial cells
    liver cells
Author
shockwave
ID
151240
Card Set
BIO 370 E3 C8 ER
Description
BIO 370 E3 C8 ER CELL GSU 2012
Updated