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2012-01-07 17:24:36

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  1. Cell membrane:
    1) a lipid bilayer that contains protein channels, enzymes, and receptors
  2. What increases membrane fluidity?
  3. What electrical charge is inside/outside of cell and why?
    Cells are negative inside compared with outside, based on Na/K ATPase (3Na+ out/2K+ in)
  4. What is the Na+ gradient used for?
    cotransport of glucose, proteins, and other molecules
  5. See page 1: Electrolytes concentrations of Intracellular and Extracellular Fluid compartments
  6. Desmosomes/hemidesmosomes
    these are adhesion molecules (cell-cell and cell-extracellular matrix) which anchor cells
  7. Tight junctions:
    these are cell-cell occluding junctions and form an impermeable barrier (i.e. epithelium)
  8. Gap junctions:
    allow communication between cells (connexin subunits)
  9. Ligand-triggered protein kinase
    receptor and response enzyme are a single transmembrane protein
  10. ABO blood type antigens:
    glycolipids on cell membrane
  11. HLA-type antigens:
    glycoproteins on cell membrane
  12. Osmotic equillibrium:
    water will move from an area of low solute concentration to an area of high solute concentration and apporach osmotic equillibrium
  13. Cell cycle:
    • 1)
    • G1
    • S (protein synthesis, chromosomal duplication)
    • G2
    • M (mitosis, nucleus divides)
    • 2) G1 most variable, determines cell cycle length
    • 3) Growth factors affect cell during G1
    • 4) Cells can also go into G0 (quiescent) from G1
  14. Mitosis:
    • 1) Prophase: centromere attachment, spindle formation, nucleus disappears
    • 2) Metaphase- chromosome alignment
    • 3) Anaphase- chromosomes pulled apart
    • 4) Telophase- separate nucleus reforms around each set of chromosomes
  15. Nucleus
    • 1) double membrane
    • 2) outer membrane continuous with rough endoplasmic reticulum
  16. Nucleolus
    • 1) inside the nucleus
    • 2) no membrane
    • 3) ribosomes made here
  17. Transcription:
    DNA strand is used as a template by RNA polymerase for synthesis of an mRNA strand
  18. Transcription factors
    • 1) bind DNA and helps the transcription of genes
    • 2) Steroid hormone- binds receptor in cytoplasm, then enters nucleus, and acts as transcription factor
    • 3) Thyroid hormone- binds receptor in nucleus, then acts as a transcription factor
    • 4) Other transcription factors: AP-1, NF-kB, STAT, NFAT
  19. Initiation factors
    bind RNA polymerase and initiate transcription
  20. DNA polymerase chain reaction
    uses oligonucleotides to amplify specific DNA sequences
  21. Purines:
    • Guanine
    • Adenine
  22. Pyrimidines
    • 1) Cytosine
    • 2) uracil (only in RNA)
    • 3) thymidine (only in DNA)
  23. Translation
    mRNA used as a template by ribosomes for the synthesis of protein
  24. Ribosomes
    have small and large subunits that read mRNA, then bind appropriate tRNAs that have amino acids and eventually make proteins

    As the ribosome moves along the mRNA, incoming aminoacyl-tRNA complexes bind to the A-site on the ribosome, after which a new peptide bond is formed with the nascent polypeptide chain previously attached to the peptide tRNA. The ribosome then moves, ejecting the now-empty tRNA and opening the A-site for the next aminoacyl-tRNA complex
  25. Glycolysis
    1 glucose molecule generates 2 ATP and 2 pyruvate molecules
  26. Mitochondria
    • 1) 2 membranes
    • 2) krebs cycle on inner matrix
    • 3) NADH/FADH2 created
  27. Krebs Cycle:
    • 1) the 2 pyruvate molecules (from the breakdown of 1 glucose) create NADH and FADH2.
    • 2) NADH and FADH2 enter the electron transport chain to create ATP
    • 3) Overall 1 molecule of glucose produces 36 ATPs.
  28. Gluconeogenesis:
    • 1) mechanism by which lactic acid (cori cycle) and amino acids are converted to glucose
    • 2) Fat and lipids are not available for gluconeogenesis because acetyl CoA (breakdown product of fat metabolism) cannot be converted back to pyruvate
    • 2) used in times of starvation or stress (basically the glycolysis pathway goes in reverse)
    • 3) Cori cycle- an elegant mechanism for the hepatic conversion of muscle lactate into new glucose. pyruvate plays a key role in this process
  29. Rough endoplasmic reticulum:
    synthesizes proteins that are exported (increased in pancreatic acinar cells)
  30. Smooth endoplasmic reticulum:
    • 1) lipid/steroid synthesis
    • 2) detoxifies drugs (increased in liver and adrenal cortex)
  31. Golgi apparatus:
    modifies proteins with carbohydrates; proteins are then transported to the cellular membrane, are secreted, or are targeted to lysosomes
  32. Lysosomes
    have digestive enzymes that degrade engulfed particles and worn-out organelles
  33. Phagosomes
    engulfed large particles; these fuse with lysosomes
  34. Endosomes
    engulfed small particles; then fuse with lysosomes
  35. Protein kinase C
    • 1) activated by calcium and diacylglyecrol (DAG)
    • 2) Phosphorylates other enzymes and proteins
  36. Protein kinase A
    • 1) activated by cAMP
    • 2) phosphorylates other enzymes and proteins
  37. myosin
    thik filaments, uses ATP to slide along actin to cause muscle contraction
  38. actin
    1) thin filaments, interact with myosin
  39. Intermediate filaments
    • 1) keratin (hair/nails)
    • 2) desmin (muscles)
    • 3) vimentin (fibroblasts)
  40. Microtubules:
    form specialized cellular structures such as cilia, neuronal axons, and mitotic spindles; also involved in the transport of organelles in the cell (form a lattice work inside the cell)
  41. centriole:
    a specialized microtubule involved in cell division (forms spindle fibers, which pull chromosome apart)