mcat science 7

  1. you can increase enzyme specificity by increasing ____ bonds ____ bonds and transient covalent bonds

    ionic bonds
  2. Arteries have ____ smooth muscle than veins

    arteries have thick walls compared to veins and are more rigid.

    Veins will expand more than arteries

    arteries are larger and more muscular than veins and more elastic
  3. arteries: 
    - more elastic
    - thicker
    - more muscular
    - more rigid
    - more smooth muscle
    - larger


    expand more
  4. formula: Formal Charge = [# of valence electrons on atom] – [non-bonded electrons + number of bonds].
  5. ionic bonds = no sigma bond
  6. small distance between HOMO and LUMO means smaller energy of light absorbed so greater wavelength (explains orange / red color of B-Carotene)
  7. C = (F-32)/1.8

    F = (C x 1.8) + 32
  8. Saponification 

    _____ hydrolyzes triglycerides to form glycerol and soap
  9. - LH surge induces ovulation

    - Ovarian follicles secrete estrogen during proliferative phase of menstrual cycle to have a 2-3 fold increase in thickness of endometrium

    - FSH plays an important role in development of ovarian follicles increasing estrogen secretion
  10. Volumetric flow rate (veins/ arteries / blood flow)

    A1V1 = A2V2

    A = Pi(r^2)

    -halve diameter halve radius
    - Area decrease by factor of 4 means velocity increase by factor of 4
  11. layrnx - houses vocal cords
  12. larger diameter and shorter length = less resistance

    V = IR
  13. 1L = 1kg

    1 pound = 0.45 kg

    1ppm = 1 mg/kg

    1ppt = 1 ng/L
  14. To increase reaction rate

    ____ vmax
    _____ km
    increase vmax

    decrease km
  15. increase pH / decrease H+ ions to increase electromotive force
  16. spontaneous reactions proceed forward and make more products
  17. fisher projection R v S: order priority then switch sign
  18. amines are ___ nucleophillic than alcohols because _______

    they are not as electronegative. More electronegativity means less nucleophillic
  19. electron and molecular geometry of atoms only differ when there is a lone pair on atoms
  20. Vitamin D when activated by parathyroid hormone promotes bone strength although it seems counter intuitive it helps counter the resorption of bone by parathyroid in the first place.
  21. Vapor pressure and boiling point

    If the solution has a higher boiling point than the pure solvent then it has a lower vapor pressure than the pure solvent because it has more solute and less water (or solvent) so it vaporize quicker but the more solutes means it takes longer to boil
  22. Add diols to ketone to create ketal to protect it from LiAlH4 reduction
  23. when hydrophobic amino acid or molecule placed in water water molecules must rearrange in order to maximize H-bonding and since hbonds cant be formed with hydrophobic molecules water is more restricted in its freedom of movement and entropy decreases
  24. lewis - electron
    bronsted - proton

    lewis base - e- donor
    lewis acid - e- acceptor
    bronsted acid - H+ donor
    bronsted base - H+ acceptor
  25. these units can be used to measure heat/energy:

    m x N
    s x W
    not W x m
  26. greater reduction potential = more likely to accept electrons
  27. hardy wein :

    - no mutations
    - large population size
    - no net migration of individuals into or out population
    - random mating
    - genes in population all equally successful at reproducing
  28. Proline - cyclic imine that introduces a bend in the protein. Found most often at beginning of alpha helices
  29. transporting Na, Cl-, and glucose out of cell requires ATP

    Transporting K+ into cell requires ATP also (Na/K+ ATPase)
  30. ADH - Increase aquaporin channels in distal collecting tubule and collecting duct
  31. H2SO4, NaCr2O7


    H2SO4, CrO3, Acetone

    Primary alcohol --> carboxylic acid
    secondary alcohol -- > Ketone
  32. PCC

    Primary alcohol --- > Aldehyde
    Secondary alcohol -- > Ketone
  33. adrenal medulla - ectoderm

    adrenal cortex , spleen, lymph vessels- mesoderm
  34. Growth in long bones occurs in the epiphyseal plates
  35. 1 mol = ____ molecules
    1 mol = 6 x 10^23 molecules
  36. Urea cycle is to safely eliminate toxic ammonia from the body. Converts ammonia to urea for excretion. 

    When amino acids are metabolized ammonia builds up in the body.
  37. SEVEN UP
    • Seminiferous tubules
    • epididymis
    • vas deferens
    • ejaculatory duct
    • nothing
    • urethra
    • penis
  38. Use H2O to make R S Chiral products from one reactant because it is Polar protic and hydrogen bonds stabilize anion intermediate and favor SN1 mechanism
  39. Ka > 10^-7 = more H+ than HA- ions
  40. Change in electrical potential:

    Delta V x q (charge)
  41. myelin sheath acts to decrease capacitance because capacitors in series have a lower net capacitance
  42. hypokalemia - low blood potassium would cause cell hyperpolarization cuz potassium would try to escape through leak channels
  43. Lyase breaks ATP to form cAMP and pyrophosphate WITHOUT use of water.
  44. coordinate covalent = when both e- are contributed by one of the atoms

    ex- ammonia + H+ = ammonium
  45. Polar covalent bond- shared electrons but large difference in electronegativity
  46. brain does not use ketones primarily until starving state not fasting state
  47. presence of chyme in duodenum causes release of brush-order enzymes like dissacharidases and peptidases

    maltase- maltose -> glucose + glucose 
    sucrase - sucrose -> glucose + fructose
    lactase - lactose -> glucose + galactose
    enteropeptidase -  Enteropeptidase converts trypsinogen (a zymogen) into its active form trypsin
  48. lower atomic radii for an atom means when bound to itself it would have a shorter and stronger bond than something with a greater atomic radii

    Nitrogen has more protons than carbon so its atomic radii is smaller and N-N bond shorter than C-C bond cuz atoms would be closer together.
  49. 6 member rings are more stable than 5 member rings due to less angle strain

    alpha anomer more stable than beta anomer because of less steric hinderance with adjacent OH group. beta anomer OH group is in cis with adjacent OH
  50. Q > keq = deltaG > 0

    so reverse reaction is favored
  51. Downfield The Nucleus feels stronger magnetic field. Deshielding is the opposite of shielding. When we say that an atom is deshielded, we mean that “A nucleus whose chemical shift has been increased due to removal of electron density, magnetic induction, or other effects.”

    so on ethylbromide the deshielded H would be near the electronegative Br- and that would be downfield

    n + 1 rule (neighbor + 1)

    downfield is closer to 10 to left and upfield is closer to 1 to right
  52. only palm of hand and sole of feet have stratium lucidum epidermal layer

    any other area of body cut would penetrate 4 layers if cut all the way through to muscle
  53. aldol formation - enolate functions as nucleophile

    H+ extracted first from OH and enolate forms to be nucleophile

    retro aldol - enolate functions as a leaving group
  54. break down products of lipids ___ ___ ____

    no break down of lipids means more cholesterol in blood
    acetyl CoA, malonyl CoA, glycerol
  55. embedded proteins - on exterior or interior of cell and involved in transcriptional changes

    peripheral proteins do not have pro-transcriptional function, exist on membrane surfaces
  56. Gq receptor increase activity of phospholipase C, which cleaves PIP2 into diacylglycerol & IP3.

    IP3 production leads to release of intracellular Ca2+ stores.
  57. chronic effects of high level of cortisol can lead to weight gain and hypertension
  58. Stable quiescent cells - only divide when needed and spend most of time in G0 (liver cells, endocrine gland, proximal tubules of kidney)

    - Vascular endothelial cells
    - Parenchymal cells of solid organs (e.g., liver, kidney, pancreas)
    - Mesenchymal cells (e.g., fibroblasts, smooth muscle)

    Permanent G0 - brain cells, neurons, heart cells, skeletal muscle cells, red blood cells (RBC precusor in bone marrow can divide).

    - Neurons of CNS
    - Cardiac and skeletal muscle


    Labile cells:

    - Epithelial cells (basal cells of skin; endometrium; mucosa lining GI, respiratory, and biliary tracts; etc.)
    - Hematopoietic cells (e.g., bone marrow stem cells)
  59. _____ cells secrete calcitonin in response to elevated calcium in blood
  60. semilumar valves comprise the aortic and pulmonic valve which prevent backflow from aorta and pulmonary arteries

    bicuspid valve prevents backflow from left ventricles to left atrium''

    tricuspid valve prevents backflow from right ventricle to right atrium

  61. double concentration of both base and acid in titration _____ buffering capacity and _____ pH
    doubles buffering capacity

    pH same
  62. these studies begin by identifying subjects with a particular outcome and restrospectively assessing risk factors
    case control
  63. RNA Pol 1- synthesize ____ to make new ribosomes.

    RNA Pol 2- DNA - > _____

    RNA Pol 3- DNA - > _____


  64. axial skeleton - skull, vetebral column, rib cage, hyoid bone

    appendicular skeleton - majority (the rest)
  65. destruction of RBC occur mostly in ____ but also occurs in liver and old RBC are phagocytized by ______

  66. concentration goes up by factor of 2 and reaction rate goes up by factor of 4 means ____ order
    second order
  67. General adaptation syndrome:
    Hormone primary in each phase

    Alarm -
    Resistance -
    • Alarm - epinephrine 
    • Resistance - Cortisol
  68. decrease products shift right

    decrease reactants shift left
  69. Indicators measure a pH change within one unit of its pKa so if you want to use an indicator to measure deviations from normal physiological pH you can use 

    ka 2 x 10^-8
    pKa = 7.8 (physiological pH = 7.4)
  70. G Cells -> parietal cells - > HCl

    chief cells -> pepsinogen

    mucous cells -> alkaline mucous
  71. UV spec- more light absorbed = less transmittance cuz less light reaches detector

    greater concentrations means more light absorbed

    to absorb light at 3 different wavelengths there must be 3 different sets of pi orbitals like in benzene

    400 cm^-1 is finger print region used to distinguish between similar species. this region is unique to each molecule, complex vibrations

    HNMR 10.5 - 12 = CARboxylic acid
    9 - 10 : aldehyde
    1- 5.5: proton in OH group
    0.9 - 1 - methyl group

    spin-spin coupling - two non equivalent protons near each other

    smaller gap between LUMO and HOMO means less energy needed to be excited, so longer wavelength absorbed with less energy carrying
  72. vaccuum filtration - when desired product in solid state

    gravity filtration- when desired product in liquid state

    vacuum distillation- preferred with molecules with high Bp 

    simple distillation- molecules below 150C DEGREES but large difference in Bp

    fractional distillation- molecules small difference in Bp and below 150C degrees
  73. TLC- .6 relative retardation vs .7 relative retardation means .7 was performed at higher temp cuz it moved farther
  74. highest peak in reaction profile = slow step

    equilibrium constant and rate constant change with temperature
  75. monosustituent alkene- kinetic product

    disubstituent alkene- thermodynamic product

    low temp- favors kinetic product when both reaction irreversible
  76. exothermic- activation energy of reverse greater than activation energy of forward
  77. specific rotation = observed rotation / c x l

    1dm = 10cm
  78. 2 mol A <-----> 1 mol B

    what change in pressure gets you to B?
    increase pressure
  79. low Kp = reverse reaction heavily favored

    homogeneous mixture- all gases or all aqueous in reaction
  80. ice less dense than water so to get ice to melt in closed container you increase the pressure because increase in pressure moves things to more dense
  81. Keq and deltaG inversely related
  82. increase temp and pOH lower (OH- greater)
  83. Kp = KcRT^n
  84. products favored = keq > 1
    reactants favored = keq <1

    products favored = deltaG -
    reactants favored = deltaG +

    changing temp changes equilibrium constant
  85. more solutes lower vapor pressure and lower the triple point on phase diagram
  86. work done by climber - mgh
  87. cooling rate = heat loss/ per unit time

    deltaQ / deltaT
  88. ion product smaller than solubility product = more of it dissolves
  89. to lower temperature without freezing to occur you increase amount of solutes to decrease freezing point 

    At the freezing point of any solution the rates of melting and freezing are exactly balanced, allowing both phases to coexist in a thermodynamically stable state. The introduction of a solute reduces the activity of the liquid phase solvent, thereby reducing the rate of freezing.

    You can think of this reduction in activity as solute molecules "getting in the way" of solvent molecules from attaining the correct alignment for freezing at the surface. On the other hand, the rate of melting is unaffected by the presence of solute because this is simply the rate of liberation from the frozen surface into the liquid phase.

    In the presence of solute, it is necessary to lower the temperature to slow down the rate of melting so that it once again matches the rate of freezing. This is why the freezing point is lowered, or depressed, by the presence of solute in the liquid phase.
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mcat science 7
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