Card Set Information

2015-05-10 23:13:58
Show Answers:

  1. isomerases
    catalyze the interconversion of isomers, including both constitutional and stereoisomers
  2. Lyases
    catalyze cleavage without the addition of water and without the transfer of electrons; the reverse reaction (synthesis) is usualy more important
  3. hydrolases
    catalyze cleavage with the addition of water
  4. oxidoreductases
    catalyze oxidation-reduction reactions that involve the transfer of electrons
  5. transferases
    move a functional group from one molecule to another molecule
  6. epimers
    differ at exactly one chiral carbon
  7. anomers
    a subtype of epimers that differ at the anomeric carbon
  8. When rings form, the anomeric carbon does what?
    alpha or beta conformation
  9. alpha-anomers
    have the --OH on the anomeric carbon trans o the free --CH2OH group
  10. Beta-anomers
    have the --OH on the anomeric carbon cis to the free --CH2OH
  11. mutarotation
    one anomeric form shifts to another, with the straight-chain form as an intermediate
  12. glycoside formation
    basis for building complex carbohydrates and requires the anomeric carbon to link to another sugar
  13. Sugars with an --H replacing an --OH group are termed __
    deoxy sugars
  14. lactose
  15. maltose
  16. sucrose
  17. Southern blotting
    can be used to detect the presence and quantity of various DNA strands in a sample; after electrophoresis, the sample is transferred to a membrane that can be probed with ssDNA molecules to look for a sequence of interest
  18. osmotic pressure
    pressure applied to a pure solvent to prevent osmosis and is related to the concentration of the solution 

  19. glucokinase
    present in the pancreatic beta-islet cells as part of hte glucose sensor and is responsive to insulin in the liver
  20. hexokinase
    traps glucose
  21. phosphofructokinase-1
    rate limiting step
  22. phosphofructokinase-2
    produces F2,6-BP, which activates PFK-1
  23. Glyceraldehyde-3-phosphate dehydrogenase
    produces NADH
  24. 3-phosphoglycerate kinase and pyruvate kinase
    perform substrate-level phosphorylation
  25. pyruvate dehydrogenase
    converts pyruvate to acetyl-CoA. Stimulated by insulin and inhibited by acetyl-CoA
  26. What are the citric acid cycle steps?
    • pyruvate--PDH-->
    • acetyl-CoA (fatty acids, ketones, alcohols)
    • citrate (citrate synthesis)
    • isocitrate
    • alpha-ketoglutarate
    • succinyl-CoA
    • sccinate
    • fumarate
    • malate
    • oxaloacetate
  27. glycogenesis
    the building of glycogen using two main enzymes:

    glycogen synthase and branching enzyme
  28. glycogen synthase
    creates alpha-1,4 glycosidic links between glucose molecules

    it is activated by insulin in the liver and muscles
  29. branching enzyme
    moves a block of oligoglucose from one chain and connects it as a branch using an alpha-1,6 glycosidic link
  30. glycogenolysis
    breakdown of glycogen using two main enzymes:

    glycogen phosphorylase and debranching enzyme
  31. glycogen phosphorylase
    • removes single glucose 1-phosphate molecules by breaking alpha-1,4-glycosidic links
    • --> in the liver, it is activated by glucagon to prevent low blood sugar; in exercising skeletal muscle, it is activated by epinephrine and AMP to provide glucose for the muscle itself
  32. debranching enzyme
    moves a block of oligoglucose from one branch and connects it to the chain using an alpha-1,4-glycosidic link
  33. gluconeogenesis
    occurs in both the cytoplasm and mitochondria, predominately in the liver

    most of gluconeogenesis is just the reverse of glycolysis, using the same enzymes
  34. The three irreversible steps of glycolysis must be bypassed by different enzymes
    pyruvate carboxylase and PEP carboxykinase bypass pyruvate kinase

    fructose-1,6-biphosphatase bypasses phosphofructokinase-1

    glucose-6-phosphatase bypasses hexokinase/glucokinase
  35. Pentose phosphate pathway
    occurs in the cytoplasm of most cells, generating NADPH and sugars for biosynthesis

    rate-limiting enzyme is glucose-6-phosphate dehydrogenase, which is activated by NADP+ and inhibited by NADPH and insulin
  36. In the postprandial/well-fed (absorptive) state, __
    insulin secretion is high and anabolic metabolism prevails
  37. In the postabsorptive (fasting) state, what happens?
    insulin secretion decreases while glucagon and catecholamine secretion increases
  38. Prolonged fasting (starvation)
    dramatically increases glucagon and catecholamine secretion; most tissues rely on fatty acids
  39. Lipids are transported via hat?
    chylomicrons, VLDL, IDL, LDL, and HDL
  40. Cholesterol metabolism
    • cholesterol may be obtained through dietary sources or through synthesis in the liver
    • the key enzyme in cholesterol biosynthesis is HMG-CoA reductase
  41. Palmitic acid
    the only fatty acid that humans can synthesize

    produced in the cytoplasm from acetyl-CoA  transported out of the mitochondria
  42. Fatty acid oxidation occurs in the mitochondria, following transport by the carnitine shuttle, via __
  43. ketogenesis
    ketone bodies form during a prolonged starvation state due to excess acetyl-CoA in the liver
  44. Ketolysis
    regenerates acetly-CoA for use as an energy source in peropheral tissues
  45. Tissue specific metabolism

    - liver
    maintains blood glucose through glycogenolysis and gluconeogenesis 

    processes lipids, cholesterol, bile, urea, and toxins
  46. Tissue specific metabolism

    - adipose
    stores and releases lipids
  47. Tissue specific metabolism

    - resting muscle
    conserves carbs as glycogen and uses free fatty acids for fuel
  48. Tissue specific metabolism

    - active muscle
    may use anaerobic metabolism, oxidative phosphorylation, direct phosphorylation (creatine phosphate), or fatty acid oxidation
  49. Tissue specific metabolism

    - cardiac muscle
    uses fatty acid oxidtaion
  50. Tissue specific metabolism

    - brain
    uses glucose except in prolonged starvation, when it can use ketolysis