Cell Bio-Carb Metabolism.txt

  1. Non-digestible carbohydrates that promote the growth of non-specific "beneficial" bacteria in the gut.
  2. specific strains of "beneficial" bacteria provided directly in a food product.
  3. Fructooligosccharides in Iams dog food are an example of...
  4. 3 pathways of glucose utilization...
    glycolysis, glycogen synthesis, hexose-monophosphate pathway
  5. 2 pathways of glucose production.
    glycogen degradation, gluconeogensis
  6. Under conditions of rapid muscle contraction, the demand for _______ to generate ATP by ______________ exceeds the ____________.
    O2; oxidative phosphorylaton; O2 supply to the muscles
  7. When the demand for ATP by oxidative phosphorylation exceeds the )2 supply to the muscles,...
    the conversion of NADH to NAD+ in the mitochondria is blocked and pyruvate accumulates as lactate
  8. Under anaerobic conditions, pyruvate is converted to ___________ by the _____________ reaction.
    lactate; lactate dehydrogenase
  9. Exercise intensity or level in which lactate is detectable in the blood.
    lactate threshold
  10. Most dietary carbohydrate is in the form of _____, which are digested by _______, enzymes that digest __________.
    starch; amylases; α-1,4 linkages
  11. Absorbed glucose enters the ________ to travel to the ________ and then to _______.
    portal vein; pancreas, liver; systemic circulation
  12. Glucose absorption occurs by...
    glucose diffusing down its concentration gradient (ie. gut lumen to mucosal cell)
  13. Glucose absorption is facilitated by a ______________.
    specific transporter or carrier protein
  14. Dietary glucose is mainly absorbed into the _____________ by _______.
    jejunal mucosal cell; SGLT-1
  15. SGLT-1 is on the _________ of the _________ for glucose absorption.
    luminal border; jejunal mucosal cells
  16. Glucose exits the jejunal mucosal cell and enters the ______ via the _______ transporter.
    portal blood; GLUT2
  17. The GLUT5 transporter carries... (2)
    fructose and a small amount of glucose
  18. The two major functions of the pancreas in carbohydrate metabolism.
    exocrine and endocrine pancreas
  19. The exocrine pancreas has function cells called ___________ that synthesize and secrete digestive enzymes into the pancreatic duct.
    acinar cells
  20. Acinar cells of the exocrine pancreas secrete ________ into the pancreatic duct to...
    α-amylase; digest dietary carbohydrates
  21. Endocrine pancreas contains function cell types called ________________, which synthesize and secrete hormones that regulate blood glucose levels.
    Islets of Langerhans
  22. Exocrine pancreas functions in...
    the digestion of dietary carbohydrates
  23. Endocrine pancreas functions in...
    regulation of blood glucose levels
  24. Alpha cells of the pancreas synthesize and secrete __________ in order to....
    glucagon; increase blood glucose levels
  25. Beat cells of the pancreas synthesize and secrete ______ in order to...
    insulin; decrease blood glucose levels
  26. The post-meal increase in blood glucose activates ___________, which lowers blood glucose by...
    insulin release; increasing glucose uptake into the tissues
  27. Glucose enters cells by _____________ with ____________.
    facilitated diffusion; glucose transporters (GLUTs)
  28. GLUT2 has ______ Km and ______ glucose affinity.
    high; low
  29. GLUT3 has _____ Km and _____ glucose affinity.
    low; high
  30. Two major cell types that express the GLUT2 transporter.
    hepatocytes (liver cells) and β cells of the pancreas
  31. Hepatocytes and β cells of the pancreas express GLUT2 because they...
    have unique mechanisms for measuring and controlling blood glucose levels
  32. The amount of glucose entering cells expressing GLUT2 is _______ over the normal (physiological) range of blood glucose levels.
    linear (because it is low affinity)
  33. GLUT3 transports ______ levels of glucose, even at _______ blood glucose concentration levels because it is expressed in cells of the ________.
    high; low; nervous system
  34. Enzymes with small values for Km will reach Vmax at...
    lower substrate concentrations
  35. Enzymes with high values for Km will reach Vmax at...
    higher substrate concentrations.
  36. Your brain doesn't know _____________, but the β cells in your pancreas do.
    what your blood glucose levels are
  37. Vmax is...
    100% uptake
  38. After a meal, the linear relationship between glucose entering hepatocytes and pancreatic β cells and blood glucose levels allows...
    the β cells to detect an increase in blood glucose and release insulin into the blood.
  39. Increased uptake of glucose into β cells via __________ results in increased glucose metabolism by...
    GLUT2; oxidation via glycolysis and the TCA cycle (thus increased ATP)
  40. An increase in ATP due to increased glucose uptake by β cells initiates closing of __________, which leads to _____________.
    K+ channels; membrane depolarization
  41. Membrane depolarization due to increased ATP production (due t increased glucose uptake by β cells) is associated with the opening of ________________, allowing...
    Ca++ channels; an increase in cellular Ca+ levels
  42. Increased intracellular Ca+ levels induces...
    translocation of insulin-containing vacuoles to the plasma membrane to be released into the blood stream by exocytosis
  43. Class of drugs used to lower blood glucose.
  44. How do Sulfonylureas lower blood glucose?
    they increase β cell insulin release by binding to and blocking the ATP-sensitive K+ channel, mimicking the increase in β cell ATP levels
  45. What are the 3 ways that insulin lowers blood glucose?
    • 1. increasing glucose uptake into "insulin responsive tissues"
    • 2. increasing the activity of pathways of glucose utilization
    • 3. decreasing the activity of pathways of glucose production
  46. What are the 2 primary and 1 somewhat insulin responsive tissues?
    muscle and adipose tissues; sometimes heart tissue
  47. Insulin lowers blood glucose by driving glucose into...
    muscle, adipose tissue, and sometimes heart tissue
  48. Insulin mobilizes _________ to the plasma membranes of ________ and _______.
    GLUT4; muscle; adipose tissue
  49. In GLUT4 transports, insulin binds to the ________, inducing _______ and increased _______ activity.
    insulin receptor; dimerization; RTK
  50. The insulin receptor kinase activity phosphorylates and activates ___________.
    Insulin receptor substrate (IRS)
  51. Insulin receptor substrate activates _____.
  52. When PI3K s activated by insulin receptor substrate, ________ and _________ are activated.
    αPKB and Atk/PKB
  53. The combined signal from αPKC and Akt/PKB activates.....
    translocation of GLUT4 to the plasma membrane
  54. hen GLUT4 is translocated to the plasma membrane, ________________ is increased, subsequently...
    glucose uptake; decreasing blood glucose levels, causing insulin levels to decrease and GLUT4 to be recycled
  55. Endocrine disorder characterized by absolute or relative lack of insulin; persistently elevated glucose.
    Diabetes mellitus
  56. Describe the β cell function in Type I Diabetes and its treatment.
    NO FUNCTIONAL β cells; daily insulin injections for life
  57. Describe the β cell function of Type II Diabetes and its treatment.
    Some variable β cell function; diet, weight loss, oral hypoglycemics
  58. With a glucose tolerance test, the 4 steps are...
    • 1. 12 hour fast
    • 2. intravenous glucose infusion
    • 3. assess blood glucose levels at 0,30,60,90,120 min after infusion
    • 4. compare to general ranges of blood glucose
  59. In healthy individuals, blood glucose levels are...
    maintained within a VERY TIGHT range
  60. On the glucose tolerance test, a healthy individual had a _______ fasting blood glucose level and a _________ in response to glucose infusion; subsequently, their blood glucose level __________.
    low; moderate rise; returned to normal
  61. On the glucose tolerance test, a diabetes type I individual had _______ fasting blood glucose level and ________ blood insulin; subsequently, their blood glucose level __________.
    an elevated; no detectable; does not decline
  62. On the glucose tolerance test, a diabetes type II individual had _______ fasting blood glucose level and a _________ in response to glucose infusion; subsequently, their blood glucose level __________.
    elevated; modest induction of blood insulin; does not significantly decline
  63. On the glucose tolerance test, an obese individual had _______ fasting blood glucose level and _________ in response to glucose infusion; subsequently, their blood glucose level __________.
    elevated; extremely high insulin levels; does not decline
  64. Obese individuals have insulin but their glucose levels cannot return to normal; this is _____________.
    peripheral insulin resistance
  65. ___________, which is non-digestible, reduces the caloric density of feed.
  66. Fiber reduces caloric density of feed by....
    slowing glucose uptake from the gut
  67. Peripheral insulin resistance (from obesity) is due to the fact that adipocytes produce ________, which bind and activate signaling pathway that interfere with ______, and ultimately....
    adipokines; insulin receptor signaling; reduce insulin dependent glucose uptake in fat and muscle cells.
  68. Glycogen is stored in...
    the muscle and liver
  69. _______ is the body's source of glucose during a fast.
    Liver glycogen
  70. _________ is the body' source of glucose for contraction within a cell.
    Muscle glycogen
  71. Although glycogen stores are a relatively small percent of total body energy,...
    glycogen storage diseases are fatal, usually in the early postnatal period
  72. Insulin activates ________ vis _______.
    glycogen synthase; protein phosphatase 1
  73. Following a meal, increased blood glucose levels cause _____________, which then bind to...
    increased insulin release from the pancreas; liver cell insulin receptors.
  74. Insulin receptor mediated signaling in the liver activates ___________, which in turn ________ and activates __________.
    protein phosphatase; dephosphorylates; glycogen synthase
  75. In addition to activating glycogen synthesis, protein phosphatase...
    dephosphorylates and deactivates glycogen phosphorylase, the enzyme that degrades glycogen
  76. Glycogen branching enzyme deficiency is a ______ disorder in Quarter Horses and always...
    autosomal recessive; results in death
  77. The first line of defense in maintaining blood glucose levels is the _________.
    breakdown of liver glycogen
  78. The fall in blood glucose is detected by __________, which release ________.
    α cells of the pancreas; glucagon
  79. The function of the hormone glucagon is to...
    increase blood glucose levels by mobilizing glucose stored in the liver as glycogen.
  80. The second line of defense in maintaining blood glucose levels during a long-term fast is ________.
  81. The primary target tissue of the hormone glucagon is _______.
  82. Glucagon's main mechanism of action is activation of ________________ of __________ and release of ______.
    GPR-mediated activation of protein kinase A (PKA); Ca+
  83. Glucagon binds to _______ and activates _______, which phosphorylates and activates _______, which degrades glycogen.
    liver cell glucagon receptor; phosphorylase kinase; glycogen phosphorylase
  84. Glucose-6-phosphate, produced by glycogen phosphorylase, is converted to "free" glucose by ___________.
  85. Glucose-6-phosphatase is only expressed in ________.
    the liver
  86. In glycogen storage disease Ia, a genetic alteration results in glucose-6-phosphatase; therefore,...
    you cannot access glycogen in the liver because you can't mobilize glycogen during a fast......G-6-P never becomes "free" glucose
  87. Epinephrine is synthesized by the _________ in response to ______.
    adrenal medulla; stress
  88. The epinephrine mechanism of action in muscle is mediated by activation of ___________ via ________ and _________.
    muscle glycogen degradation; protein kinase A (PKA); phosphorylase kinase (PK)
  89. During rigorous exercise, _______ levels increase.
  90. Epinephrine binds to ___________ and activates _______, which converts ATP to cAMP.
    muscle cell epinephrine receptor; adenyl cyclase
  91. Epinephrine receptor mediated signaling activates _________, which phosphorylates and activates ___________, which degrades glycogen.
    phosphorylase kinase; glycogen phosphorylase
  92. Glucose-6-phosphate is oxidized via the ___________ and the ________ to generate ATP for muscle contraction.
    glycolytic pathway and TCA cycle
Card Set
Cell Bio-Carb Metabolism.txt