Phys Ch21 Exam2

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Phys Ch21 Exam2
2011-10-16 18:24:28
Phys Ch21 Exam2 Metabolism

Phys Ch21 Exam2 Metabolism
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  1. Concept that cells perform certain metabolic pathways based on what tissue/organ they're a part of
  2. 3 ways in which nutrients are utilized after intake
    • catabolized for energy
    • substrates for new molecules
    • stored for energy
  3. 3 types of carbs our bodies use
    • glucose (for energy)
    • glycogen (for storing energy)
    • polysaccharides (for glycoproteins on cell membranes)
  4. Proteins which carry triglcyerides around in blood
    HDL, LDL
  5. Where are FAs & monoglycerides absorbed?
    GI tract
  6. After being absorbed in GI tract, what happens to FAs & monoglycerides? (3 steps)
    • Reassembled into triglycerides by epithelial cells
    • TGs get carried around in blood by lipoproteins
    • TGs in capillaries broken down by LPL into FAs & monoglycerides
  7. Enzyme which breaks TGs into FAs & monoglycerides
    Lipoprotein lipase (LPL)
  8. FAs are lipids which are used for:
    energy & synthesis of phospholipids
  9. Energy expended per unit of time
    Metabolic rate
  10. Rate of energy expenditure of a person awake, resting, lying down, and fasted for 12 hours
    Basal metabolic rate (BMR)
  11. Why is BMR measurement useful?
    Measures minimum energy expenditure necessary to maintain body functions
  12. Energy output is made up of ___ (~ 60%) + ____ (~40%)
    • heat
    • work
  13. When would someone have a positive energy balance?
    When energy intake > energy ouput. This causes weight gain.
  14. When would someone have a negative energy balance?
    When energy intake < energy output. This causes weight loss.
  15. Intake of food causes less energy output; nutrients absorbed or stored
    Absorptive state
  16. 3-4 hours after eating; stored nutrients are broken down & used; glucose spared for nervous system (brain)
    Post-absorptive state
  17. Glycogen is made up of _____ _____
    phosphorylated glucose
  18. Breakdown of glycogen in muscle cells vs in liver cells
    • In muscle cells produces glucose-6-phosphate which can't leave muscle cell
    • In liver cells, glucose-6-phosphate is broken down by glucose-6-phosphatase (removes phosphate group) so glucose can leave liver & enter blood
  19. Food metabolism regulation by: (3)
    • Hormones (insulin during absorption & glucagon during post-absorption)
    • Epinephrine (sympathetic nervous system) (minor)
  20. Normal blood glucose range
    70-100 mg/dL
  21. Insulin secreted by
    Beta cells of pancreas
  22. Metabolism hormone which promotes synthesis of energy storage molecs (anabolic rxns)
  23. Secretion of insulin increased by (2)
    • Increased concentration of glucose, AAs, or GIPs in blood
    • Also stimulated by parasympathetic nervous system
  24. Hormone secreted by cells in the wall of the GI tract which prepares body for transitions to absorptive state by triggering insulin secretion in advance
    GIP (Gluose-dependent insulinotropic peptide)
  25. Secretion of insulin decreased by (2)
    • Decrease in bs
    • Sympathetic nervous system (epinephrine)
  26. Actions of insulin: (3)
    • Anabolism to store energy (synthesis of glycogen & TGs)
    • Increase glucose uptake by cells
    • Decrease catabolism
  27. Peptide hormone which is secreted from alpha cells of pancreas
  28. Metabolism hormone which promotes breakdown of energy stores so they can be used; mainly by utilizing FAs so that glucose is spared for nervous system
  29. Secretion of glucagon is triggered by:
    • Low bs
    • Epinephrine (sympathetic nervous system)
  30. Actions of glucagon
    • Catabolism of glycogen (glycogenolysis) & TGs (lipolysis)
    • Gluconeogenesis (from glycogen)
  31. Sympathetic nervous system is
    fight or flight response
  32. Parasympathetic nervous system is
    returns things to normal
  33. The _____ nervous system suppresses insulin release & stimulates glucagon release
    Sympathetic autonomic nervous system
  34. Autonomic nervous system consists of: (2)
    • Sympathetic ANS
    • Parasympathetic ANS
  35. Growth hormone, Insulin-like growth factors (IGF aka somatomedins), Insulin, Thyroid hormones, Sex hormones are all hormones that affect
  36. Term for increase in cell size
  37. Term for increase in cell number
  38. Metabolic actions which help growth (5)
    • Fat breakdown
    • Gluconeogenesis in liver
    • Release of IGF
    • "Glucose sparing" (keep it in blood instead of cells)
    • Uptake AA into cells
    • (these are all similar actions of glucagon)
  39. Concept of "glucose sparing"
    Increase of blood glucose instead of going into fat & muscle cells
  40. GH works mostly via ____ by stimulating it's release from liver & other cells
    IGF (somatomedins)
  41. IGFs effect target cells as ___ or as ____
    hormone or paracrine
  42. ___ ___ regulate GH secretion and include 2 types:
    • Tropic hormones
    • GH Releasing Hormone (GHRH)
    • GH Inhibiting Hormone (GHIH)
  43. How do tropic hormones regulate GH secretion? (ie where)
    GHRH or GHIH from hypothalamus inhibits GH release from anterior pituitary
  44. 2 hormones which are required (ie permissive) for GH actions
    insulin, thyroid hormones
  45. Hormone which inhibits growth but is still permissive for GH secretion
  46. ___ : lipophilic (bind to nuclear receptors & cause increased transcription), control BMR, if there's little then more energy is stored, are required for epinephrine receptor expression (so are permissive for sympathetic nervous system)
    thyroid hormones
  47. During stress more __ and __ are secreted to mobilize energy stores. Also bp is ___
    • Epinephrine, glucocorticoid (ie increased sympathetic nervous system activity)
    • maintained
  48. Thyroid concentration:
    ____ concentrations increase ___ ___
    ____ concentrations increase ___ ___
    • High; energy mobilization
    • Low; energy storage
  49. Cortisol is anabolic or catabolic? How does it affect immune system? How is it controlled?
    • catabolic
    • suppresses it
    • by tropic hormones
  50. Thermal energy through electromagnetic waves
    (body heat --> air ---> walls)
  51. Thermal energy through contact
  52. Heat transfer by mvmt of fluid or air
  53. Central thermoreceptors are found in ____ and peripheral thermoreceptors are found mostly in ___
    • hypothalamus (where thermoregulatory center is located)
    • skin
  54. Thermoneutral zone is aka and the range is:
    • room temp
    • 20-30 C (77-86 F)
  55. Increase or decrease in vessels to alter body temp
  56. 2 heat-generating mechanisms
    • Shivering thermogenesis
    • Nonshivering thermogenesis
  57. Growth Hormone v. Cortisol
    • Growth Hormone
    • • Stimulates energy store breakdown
    • • Stimulates glucose sparing
    • • Supports growth actions (ieprotein synthesis)
    • • Controls insulin-like growth factors (IGFs) which promote growth
    • Cortisol
    • • Stimulates energy store breakdown
    • • Stimulates glucose sparing
    • • Very few actions that support growth
    • • Actually increases protein breakdown
    • • No IGF signaling