Ch 9: Energy Metabolism

  1. intermediates:
    compounds formed in a pathway
  2. metabolic pathway:
    biochemical reactions that occur in progression from beginning to end
  3. anabolic:
    pathways that build compounds (uses energy)
  4. catabolic:
    pathways that break compounds (release energy)
  5. metabolism:
    • the entire network of chemical processes involved in maintaining life
    • encompasses all of the sequences of chemical reactions that occur in the body
  6. cellular respiration:
    oxidation of food molecules to obtain energy
  7. What is ATP, where is the energy located
    • body's source of energy derived from catabolic reactions
    • bonds between phosphates are high energy bonds
  8. how much ATP present in the body
    0.22 lbs at one time
  9. oxidation-reduction reactions:
    electrons (and H+ ions) are transferred through reactions from energy-yielding compounds to oxygen
  10. oxidized:
    • loses one or more electrons/hydrogens
    • OR
    • gains one or more oxygen molecules
    • highly reactive
  11. reduced:
    • gains one or more electrons/hydrogens
    • OR
    • loses one or more oxygen molecules
  12. dehydrogenases:
    • remove H+ from energy-yielding nutrients
    • H+ transferred to O- to form water (H2O)
    • energy transferred to ADP to generate ATP
  13. Coenzymes: & two examples
    • assist enzymes
    • NAD+
    • FAD
  14. Nicotinamide adenine dinucleotide:
    • NAD+
    • made of vitamin Niacin
    • becomes NADH + H+ in oxidation-reduction reactions
  15. Flavin adenine dinucleotide:
    • FAD
    • contains vitamin Riboflavin
    • becomes FADH2
  16. stages of anaerobic metabolism:
    • direct phosphorylation
    • glycolysis
  17. stages of aerobic respiration:
    • transition reaction
    • citric acid cycle
    • electron transport chain
  18. CP:
    • creatine phosphate
    • stored in muscle
    • when it splits, it donates a phosphate to ADP to make ATP
  19. net ATP made by aerobic vs anaerobic respiration
    • anaerobic - 2 ATP
    • aerobic - 30-32 ATP
  20. 2 main roles of glycolysis
    • break down carbs to generate energy
    • provide building blocks for synthesizing other compounds
  21. entrants and products of glycolysis
    • enter - glucose
    • exit - 2 pyruvates
  22. what is the Cori cycle
    • pyruvate is converted to lactate in the absence of oxygen
    • lactate is then picked up by liver to synthesize compounds used in aerobic metabolism
  23. Gist of transition reaction
    • synthesis of acetyl-coA
    • occurs in mitochondria
    • 0 ATP produced
  24. Gist of Citric Acid/Krebs Cycle
    • acetyl-coA + oxaloacetate -> citrate
    • which is then converted back to oxaloacetate
    • 1 ATP from each GTP = 2 ATPs
  25. Gist of electron transport chain
    • requires oxygen + copper and iron
    • electrons pass along ETC -> H+ are pumped into intermembrane space -> creates concentration gradient -> ATP synthase allows H+ back in and captures energy for production of ATP
    • 32 ATP total
  26. how is glycogen used for ATP production
    • vitamin B6 converts it into glucose-posphate
    • which then enter glycolysis
  27. how is ATP made from lipids
    • lipolysis = triglycerides broken into fatty acids and glycerols
    • beta-oxidation = fatty acids broken into many acetyl-coA molecules
    • the acetyl-coA then enters the citric acid cycle
    • 7 atp/carbon from each fatty acid
  28. role of oxaloacetate
    • without it, CTA cycle slows down, and ATP wont be produced
    • combines with acetyl-coA to form citrate
  29. how are ketone bodies formed
    • by incomplete fatty acid oxidation
    • due to inadequate insulin production
  30. ketosis:
    too many ketone bodies
  31. diabetic ketoacidosis:
    • lack of insulin inhibits normal CHO and fat metabolism
    • excess of ketones in blood
    • excretion in urine also depletes Na and K
    • blood becomes acidic
    • can lead to coma or death, needs to be treated with insulin/fluid/electrolytes
  32. how does ketogenesis occur
    • low carb diet ->
    • not enough oxaloacetate ->
    • citric acid cycle activity decreases while lipolysis continues meaning buildup of acetyl-coA ->
    • acetyl-coA cant enter CTA bc no oxaloacetate ->
    • so they join together and form ketone bodies
  33. deamination:
    removal of amino group
  34. gluconeogenesis:
    forming glucose from glucogenic amino acids and other compounds
  35. what happens during fasting
    • initially body uses stored glycogen and fatty acids from adipose
    • as glycogen stores decrease, lean muscle broken down to convert AA to glucose (gluconeogenesis)
    • loss of protein from body tissues occurs til body adapts to using ketones for fuel
Card Set
Ch 9: Energy Metabolism
energy metabolism