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2012-05-07 20:27:22
nutrition metabolism

nutrition and metabolism
Show Answers:

  1. any ingested chemcial that is used for growth, repair, or maintenance of the body is called:
  2. water, carbohydrates, lipids, and proteins are considered:
    macronutrients, because they must be consumed in relatively large amounts
  3. minerals and vitamins are called:
    micronutrients, becuase only small quantities are required
  4. describe water's role in maintaining body function:
    • solvent; coolant
    • reactant or product in many metabolic rxns (especially hydrolysis and condensation)
    • dilutes and eliminates metabolic wastes
    • supports blood volume and pressure
  5. describe carbohydrate's role in maintaining body function:
    • fuel
    • a component of nucleic acids, ATP and other nucleotides, glycoproteins, and glycolipids

    dietary carbohydrates come in 3 forms: monosaccharides (glucose, galactose, fructose), disaccharides (sucrose, lactose, maltose), polysacchrides (starch)
  6. describe lipids role in maintaining body function:
    • fuel
    • plasma membrane structure
    • myelin sheaths of nerve fibers
    • hormones
    • bile acids
    • insulation
    • protective padding around organs
    • absorption of fat-soluble vitamins
    • vitamin D synthesis
    • some blood-clotting factors

    • contain 2x engery/gram than carbohydrates
    • mostly stored energy - fat
    • 30% from animals
  7. describe the lipoprotein chylomicron and how it is transported throughtout the body:
    90% triglyceride

    • lymph absorbs chylomicrons from small intestine
    • lymph drains into the bloodstream
    • lipoprotein lipase removes lipids from chylomicrons
    • a. liver disposes of chylomicron remnants
    • b. lipids are stored in adipocytes or used by other celles
  8. describe the lipoprotein very low density lipoprotien and low density lipoproteins, and how it is transported throughout the body:
    • produced by the liver, transports lipids to the adipose tissue for storage, 55% triglycerides, 20% cholesterol, when triglycerides are removed in the adiopose tissue, the VLDLs become LDLs and contain mostly cholesterol
    • cells absorb LDLS by receptor-mediate endocytosis
  9. describe the lipoprotein high density lipoprotein, and how it is transported throughout the body:
    produced by the liver, produces an empty, collapsed protein shell, shell travels in blood and picks up cholesterol and phospholipids from other organs, next time it ciculates thru the liver, the liver removes the cholesterol and elimiates it as either cholesterol or bile acids
  10. describe proteins role in maintaining the body function:
    • muscle contraction
    • structure of cellular membranes and extracelluar material
    • enzymes
    • major component of connective tissue
    • transport plamsa lipids
    • blood clotting factors
    • blood viscosity and osmolaryity
    • antibodies
    • immunge recognition
    • buffers
    • emergency fule
  11. describe minerals role in maintaining the body fucntion:
    • structure of bones and teeth
    • componet of some structural proteins, hormones, ATP, phospholipids
    • cofactors for many enzymes
    • electrolytes
    • oxygen transport by hemoglobin
    • buffers
    • stomach acid
    • osmolarity of body fluids
  12. describe vitamines role in maintaining body function
    • coenzyems for metabolic pathways
    • antioxidants
  13. describe the process of glycogenesis:
    • the synthesis of glycogen, stimulated by insulin
    • glucose is attached to a growing polysaccharide chain
  14. describe the process of glycogenolysis:
    the hydrolysis of glycogen, relaeses glucose between meals when new glucose is not being ingested, stimulated by glocagon and epinephrine
  15. describe the process of gluconegenesis:
    the synthesis of glucose from noncharbohydrates such as glycerol and amino acids
  16. describe the process of lipogenesis:
    sythesizing fats from other types of molecules, such as sugars and amino acids
  17. describe the process of lipolysis:
    stimulated by epinephrin, norepinephrine, is the break down of fat for fule, the glycerol and fatty acids are furhter oxidized
  18. describe the role of the liver in metabolism:
    • carbohydrate metabolism: stabilizes blood glucose concentration by stroing excess glucose for glycogenesis, gluconeogensis, and glycogenolysis
    • lipic metabolism: carries out liopgenesis, and synthesizes cholesterol and phospholipids, produces VLDS
    • protein and amino acid metabolism:
    • synthesis of plamsa proteins:
    • vitamin and mineral metabolism
    • digestion: bile acids, lecithin, detoxic alcohol, antibodies
  19. describe the absorptive state and postabsorptive state for regulatory hormones:
    • absorptiive: principally insulin, also gastrin, secretin, CCK
    • postabsorptive: principally glucagon, also epinephrine, growth hormones
  20. describe the absoptive and postabsorptive state for carbohydrate metabolism
    • absorptive
    • blood glucose rising
    • glucose uptake
    • glucose stored by glycogenesis
    • gluconeogenesis suppressed

    • postabsorptive
    • blood glucose falling
    • glucose released by glycogenolysis
    • gluconeogenesis stimulated
  21. describe the absorptive and postabsorptive state for lipid metabolism:
    • absorptive
    • lipogenesis occuring
    • lipid uptake from chylomicrons
    • lipid storage in fat and muscle

    • postabsorptive
    • lipolysis occuring
    • fatty acids oxidized for fule
    • glycerol used for gluconeogenesis
  22. describe the absorptive and postabsorptive states for protein metabolism
    • absorptive
    • amino acid uptake, protein synthesis
    • excess amnio acid burned as fuel

    • postabsorptive
    • amnio acids oxidized of glycogen and fat stores are inadequate for energy needs