Biochem part 2

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Biochem part 2
2013-03-24 12:34:55

Includes the example review questions she asked at the of lecutre
Show Answers:

  1. Basic structure of Carbs is...
    Aldehydes or ketones with multiple –OH groups
  2. Glucose is a monosaccharide, what is the molecular formula?
  3. General formula for a monosaccharide is:
    C-H2O or literally a “carbon hydrate”

    3-9 carbons
  4. monosaccharides linked =
    Polysaccharide=monosaccharides linked
  5. What is the monomer unit of a carb?
    Monomer unit is the monosaccharide
  6. True or false? 
    Carbohydrates make up most of the organic matter on earth & play an extensive roles in all forms of life.
  7. What kind of glucose do we usually talk about? (D glucose or L glucose?)
    We're used to using glucose and dextrose interchangeably. But really dextrose is D-glucose, last OH is on R  so that’s why it’s D glucose or Dextrose
  8. Name the roles of the carbohydrates (there are six!)
    Energy stores


    Metabolic intermediates

    Structural framework of DNA/RNA

    Structural elements of cell walls

    Mediators of cellular interactions
  9. True or false. We can only use the L types of monosaccharides.
    False! We can only use the D type!
  10. How do carbohydrates get stored in the body?
    Carbs get stored in body as glycogen.  We use glucose for fuel, Use it for fuel, need to break glycogen down to it’s component parts for  glucose.
  11. Sucrose (table sugar) is made up of
    Sucrose is a disaccharide made of D-fructose (monosaccharide found in fruit, aka fruit sugar) and D-glucose
  12. Lactose is made up of
    D glucose and D galactose
  13. When 2 glucose molecules come together it is...
    maltose (disaccharide with two glucoses together)
  14. Describe Catabolism
    Breakdown of fuel sources by. . .

    Oxidation of food molecules to produce fuel

    Converts fuel into cellular energy
  15. True or false. Metabolism is both catabolism and anabolism
  16. Describe Anabolism
    • Build up of body tissue from dietary sources
    • (ex: take in glucose and form glycogen)
  17. Food (fuel) + inspired air (oxygen) →
  18. During the first stem of metabolism, carbohydrates are converted to polysaccharides. What is the first enzyme to help digest our food?
    The first enzyme to help is amylase (is in our saliva). Works both in mouth and esophagus at slightly acidic pH. Amylase gets inactivated in stomach d/t acidity (lower pH).
  19. What happens in the stomach, once the polysaccharides are monosaccharides?
    We have continuation because acid hydrolysis continues the breakdown  process.Proteins and fats also getting broken down (at same time) by protease and lipases.
  20. What happens in the stomach once the food is in the small intestine?
    Once food into small intestine,amylase again continues the breakdown of carbohydrates, amylase now secreted by pancreas. Ultimately almost a complete conversion of whatever carb we digested to simple monosaccharide units. So the glucose and whatever other simple sugars result,get transported across intestinal wall to hepatic portal vein.
  21. From the hepatic portal vein, what happens to the glucose or whatever other simple sugars we digested?
    Goes to liver and other tissues where they get converted to fatty acids, AA, glycogen continue to be oxidized by other metabolic pathways.
  22. Glucose is oxidized by glycolysis and the end result is ____ or ____ (depending on if oxygen is present).
    So again, glucose is oxidized by glycolysis, end result is lactic acid or pyruvic acid. If oxygen present, aerobic process, ends in pyruvate. Difference between them is if oxygen is absent, its anaerobic, then it ends in lactic.
  23. Law of conservation of energy:
    energy can be converted from one form to another but can’t be created or destroyed
  24. How is energy produced?
    Produced by the oxidation of biomolecules consisting mainly of carbon, hydrogen, & oxygen

    End products are carbon dioxide, water, & energy
  25. CHO, proteins, & lipids differ instructure & broken down in differentinitial pathways but all end up in
    the citric acid cycle & oxidative phosphorylation
  26. Oxidation by definition is
    loss of electrons or loss of hydrogen or gain of oxygen
  27. When we oxidize glucose to carbon dioxide and water, we end up releasing free energy by____kcal/mol
    686 kcal/mol (it releases a lot of energy oxidizing glucose down to CO2 and water)
  28. True or false.
    We take in our food (lipids, carbs, proteins) they all come together to intermediary (acetyl SCoA) which goes into citric acid cycle and the electron transport chain.
  29. Our basal metabolism is that we produce __kcal/kg/hr if male or about ___kcal/kg/hr if female
    • 1kcal/kg/hr if male
    • 0.95kcal/kg/hr if female
  30. Mitochondria aka the Cell Powerhouse produces ___% of ATP
  31. True or false.
    Mitochondria comes from the father.
    • FALSE!
    • all comes from mom (develops from eggs).
  32. TRUE or FALSE.
    Mitochondria have their own DNA, synthesize proteins, and can replicate without assistance.
  33. Where exactly do the ATP production and Krebs cycle take place in the mitochondria?
    • The folds! (increases surface area for metabolic pathways to take place)
    • This is where citric acid cycle and electron transport occur.
  34. Glycolysis (aka Embed-Meyerhof Pathway) occurs in the ____ and is series of reactions that converts ___ molecule(s) of glucose into ___ molecule(s) of pyruvic acid + __ energy (ATP)
    Occurs in cytoplasm

    • Series of reactions that convert 1
    • molecule of glucose → 2 molecules of pyruvic acid +energy (ATP)

    Glucose → 2 pyruvate + 2 ATP
  35. True or false.
    Glycolysis can occur with or without the presence of oxygen.
    • TRUE.
    • If oxygen is present it creates pyruvate. 
    • If oxygen is not present, it creates lactic acid.
  36. What happens at the end of glycolysis when oxygen is present....
    End of glycolysis, pyruvate by mediatory of Aceytl CoA goes into citirc acid cycle and electron transport train
  37. Name two reasons glucose is such an important source of energy in mammals...
    mammals glucose is only fuel brain uses under non starvation conditions. And it’s the only fuel that RBC can use at all. So glucose is very important energy source.
  38. Acetyl Co-A is the intermediate in the breakdown of all classes of food molecules. What does it do?
    Carries the acetyl groups into the common pathways of catabolism – the citric acid cycle & electron transport, ATP production

    *Also used in the synthesis of acetylcholine
  39. What are the two other names for the citric acid cycle?
    Tricarboxylic acid cycle (TCA)

    Kreb’s cycle
  40. Describe the Citric Acid Cycle.
    common pathway for oxidation of fuel molecules which enter the cycle as acetyl CoA

    • Breakdown of acetyl groups (from acetyl
    • CoA) results into 2 molecules of carbon dioxide + energy carried by reduced coenzymes

    Primary function is the harvesting of high energy electrons to enter oxidative  phosphorylation & ATP generation
  41. Can the citric acid cycle occur without oxygen?
    NO! Citric Acid cycle is only aerobic
  42. TRUE or FALSE
    Most ATP generated comes from citric acid
    cycle and phosphorylation.
  43. Describe the oxidative phosphorylation.
    Occurs in mitochondria

    • High energy electrons from the citric
    • acid cycle

    • Occurs in a number of electron-transfer
    • reactions which take place in a set of membrane proteins known as the electron
    • transport chain (respiratory chain)

    ATP is formed
  44. Oxidative Phosphorylation synthesizes of ATP using energy released in electron transport chain with aid of coenzymes. Name those co-enzymes
    NAD and CoQ
  45. How is ATP formed from ADP?
    Produced from ADP, add a phosphate group on phosphoralate and get ATP (requires input of energy).... as bonds are broken, hydrolysis of ATP, energy gets released.
  46. ATP hydrolysis releases...
    ENERGY (1200kcal/mol to be exact!)
  47. There are many uses of ATP energy. List them
    • active transport of molecules across cell membrane
    • work of muscle contraction
    • synthesis of various hormones
    • conduction of nerve action potentials
    • cell division and cell growth-
  48. Complete metabolism of 1 mole of glucose
    through glycolysis & the citric acid cycle yields ___ moles of ATP
  49. anaerobic glycolysis in which glucose is converted to lactate is a net of __ moles of ATP
  50. What is one reason for hyperglycemia from a surgical stimulus?
    • surgical stimulus =release of catecholamines & cortisol
    • Hyperglycemic because circulating amount of insulin does not increase proportionally to level of glucose, both increase but glucose increases more than insulin, end result is hyperglycemia.
  51. Describe Hepatic glycogenolysis
    • Glucagon is released normally from alpha cells of pancreas (insulin from beta cells of
    • pancreas)

    Glucagon causes breakdown of stored glycogen into glucose. This doesn’t really change with surgical stimulation (Secretion does not change with surgical stimulation). (The breakdown of glycogen to glucose) but still have glycogneoolysis, the increase in glucose we tend to see is from glycogenolysis.
  52. Another metabolic effect of surgery or trauma is gluconeogenesis, describe it.
    make glucose from non-carbohydrate sources like proteins or lipids
  53. In response to surgery or trauma, catecholamines and cortisol will help increase blood sugar, how?
    Catecholamines and cortisol will facilitate gluconeogenesis (making glucose from other sources) and glycogenolysis (glycogen making glucose)
  54. Protein catabolism is a metabolic effect in response to surgery or trauma, describe this...
    Amino acids released from breakdown of proteins. AA go and contribute to gluconeogenesis and also contributes to loss of lean muscle mass. 

    Weight loss up to 0.5 kg of lean body mass/day
  55. Name the structural types of lipids
    Esters or amides of carboxylic acids

    Long,straight chain hydrocarbons (fatty acids)

  56. True or False.
    Lipids are naturally occurring molecules from a plant or animal that is soluble in nonpolar organic solvents but not in water
  57. What are the three roles of lipids?
    Energy storage

    Cell membrane-maintain two aqueous environments separate from each other

    Chemical messengers- in endocrine & elsewhere (like steroid hormones -cortisol and aldosterone)
  58. There are three types of cell membrane lipids
    Phospholipids (Basic structure of cell membrane)


  59. Describe the characteristics of the cell membrane
    • 1)Composition:
    • Phospholipid bilayer
    • Includes cholesterol, proteins (including
    • glycoproteins), & glycolipids

    • 2)Permeability & transportation across the membrane:
    • Simple vs facilitated diffusion
    • Active transport
  60. Glucose goes through cell membrane by...
    Facilitated diffusion
  61. ICF makes up what percent of total body fluids?
  62. Plasma makes up what percent of body fluids?
  63. Interstitial fluid makes up what percent of body fluids?
  64. Minor components make up what percent of body fluids?
  65. I & O

    Food & drink = ___ ml

    Oxidation of food = ___ ml
    • Food & drink = 2200 ml
    • Oxidation of food = 300 ml
  66. Kidneys maintain water & electrolyte balance by increasing or decreasing amounts eliminated mediated by…
    • Hormone secretion (ADH)
    • --Osmoreceptors 
    • --Aquaporins
  67. The defect in sickle cell anemia is a
    problem with the ___ structure of proteins
  68. TRUE or FALSE.
    Competitive enzyme co-inhibition is controlled by the relative concentrations of the substrate and the inhibitor

  69. Acetylcholine is the neurotransmitter
    found at the
    1: sympathetic ganglion
    2: parasympathetic ganglion
    3: sympathetic end organ
    4: parasympathetic end organ
    5: neuromuscular junction
    • 1: sympathetic ganglion
    • 2: parasympathetic ganglion end organ
    • 4: parasympathetic end organ
    • 5: neuromuscular junction
  70. Chemically most neurotransmitters are:
  71. True cholinesterase
    1. is present in plasma
    2. Is present in neuromuscular junction
    3. Hydrolyzes acetylcholine
    4. Hydrolyzes succetylcholine
    5. Is also known as aceytlcholinesterase
    • 2. Is present in neuromuscular junction
    • 3. Hydrolyzes acetylcholine
    • 5. Is also known as aceytlcholinesterase
  72. Carbs are either ___ or ___ with multiple
    ___ groups
    • Aldehydes or Ketones with multiple
    • hydroxyl groups
  73. Dextrose is….
    the D isomer of glucose
  74. Oxidation is

    a)A reaction that consumes energy
    b)A reaction that releases energy
    c)A reaction in which there is a loss of electrons
    d)Both A and C
    e)Both B and C
    • E. (both B and C)
    • A reaction that releases energyc & a reaction in which there is a loss of electrons
  75. The breakdown of all molecules is to...
    Acetylcholine Coenzyme SCoA
  76. Adrenergic Beta 1 is located where?
    postsynaptic membranes in the heart
  77. Adrenergic β2 – is located where?
    postsynaptic in smooth muscle and glands
  78. Adrenergic Alpha 1 is located where?
    • α1  - postsynaptic located in smooth muscle
    • throughout the body, in the eye, lung, blood vessels, uterus, gut, & GU
    • system
  79. Adrenergic Alpha 2 is located where?
    α2  - presynaptic nerve terminals