mcat science 2

  1. -tRNA cloverleaf

    -stemloop in rho-independent termination

    -psuedoknot in telomerase

    -70 nucleotide hairpin structure

    all examples of _____
    secondary structures of nucleic acids
  2. must have one restriction enzyme for insertion of foreign DNA (an enzyme produced chiefly by certain bacteria, having the property of cleaving DNA molecules at or near a specific sequence of bases.)

    must have bacterial origin of replication to allow for replication and maintenance of vector in host cell

    must have host transcription initiation sequence
    needed for plasmid vector to ensure expression of mRNA
  3. _____ cells contain no nuclei and therefore don't produce mRNA or translate protein.

    so something that effects gene expression (translation) won't effect this.
    Red blood cells - erythrocytes
  4. - most bacteria genomes contain no _____

    - all bacterial transcription is conducted by a single type of RNA Pol - T or F?
    introns

    True
  5. progenitor cell potency:

    - Gene activation potential to generate into multiple but limited cell types (hematopoetic cell that can differentiate into lymphocytes, monocytes, neutrophils but no other lineage). Mesenchymal stem cells - only give rise to connective tissue (osteoblast- bone cells, chondrocytes- cartilage cells, adipocytes- fat cells)


    - Can differentiate into only one cell type although not sure if this exist

    - single cell can divide to produce all differentiated cells in an organism (zygote)

    - can give rise to any of the cells in the 3 germ layers - endoderm (tissue lining GI, respiratory) --- mesoderm (muscle, bone, blood, lining of most urogential) ---- ectoderm (epidermal and nervous tissue)
    - multipotent 

    - unipotent 

    - totipotent 

    - pluripotent
  6. Post transcriptional modifications of RNA take place in the ______

    this includes ____ and ____ additions which are required for export to _____
    nucleus

    5'cap 

    poly-A tail

    cytoplasm
  7. prokaryotes reproduce by ______
    binary fission
  8. Mitosis mnemonic


    P arty
    M ore
    A t 
    T he
    C lub
    • interphase
    • prophase
    • metaphase
    • anaphase
    • telophase
    • cytokinesis
  9. which cell type least likely to be found in G0 phase of cell cycle

    liver
    neuron
    epithelial
    kidney
    epithelial cuz they divide the most out of these

    neurons in G0 almost all the time cuz they dont divide in adults
  10. There are ____ glycerol molecules and ____ fatty acid molecules in a triglyceride
    1

    3
  11. beta oxidation- fatty acids broken down to acetylcoA to be fed to citric acid cycle. Beta oxidation generates electron carriers NADH and FADH2 which produce energy for ETC. beta carbon of each fatty acid oxidized to C=O.

    step 1- form c=c bond between alpha and beta carbons of carbonyl group at the head of acyl-coA molecule

    step 2- ---OH group added to beta carbon

    step 3- C-OH bond on beta carbon is oxidized to C=O and NADH is formed.

    step4- molecule gets broken up yielding a acetyl-coA and smaller acyl-coA group
    beta oxidation- fatty acids broken down to acetylcoA to be fed to citric acid cycle. Beta oxidation generates electron carriers NADH and FADH2 which produce energy for ETC. beta carbon of each fatty acid oxidized to C=O.

    step 1- form c=c bond between alpha and beta carbons of carbonyl group at the head of acyl-coA molecule

    step 2- ---OH group added to beta carbon

    step 3- C-OH bond on beta carbon is oxidized to C=O and NADH is formed.

    step4- molecule gets broken up yielding a acetyl-coA and smaller acyl-coA group
  12. beta oxidation occurs in ____
    mitochondria
  13. SDS PAGE

    - SDS molecule denatures the protein into its unfolded polypeptide state so shape doesn't interfere with how it travels

    - The more positively charged molecules on a protein the _______ a distance it will travel
    smaller- because the more negative it is the more it will travel toward positive end of apparatus
  14. List purines

    List pyrimidines 

    which have single ring structure?

    Which have 2 ring structure?
    Purines- Guanine and Adenine 

    Pyrimidines- Cytosine, Uracil, Thymidine

    single- pyrimidines

    purines- 2 ring
  15. forms of secondary structure that exist as a result of hydrogen bonding between amino acid backbone atoms
    a-helix and b-sheet
  16. SN2 mechanism is favored by ______ solvents like _____ and DMSO

    SN1 mechanism is favored by _______ solvents like _____ and _____
    - polar aprotic

    - acetone

    - polar protic

    - water

    - ethanol


    In general terms, any solvent that contains a labile H+is called a protic solvent. The molecules of such solvents readily donate protons (H+) to reagents. Conversely, aprotic solvents cannot donate hydrogen.
  17. R vs S atoms with higher atomic number have higher priority and right is R and S is left
    R vs S atoms with higher atomic number have higher priority and right is R and S is left
  18. all enzyme active site filled = 

    km =
    VMAX

    1/2VMAX
  19. L and D amino acids- which do eukaryotes use and which do prokaryotes bacteria use?
    eukaryotes - L-amino acids only (L- living eukaryotes)

    prokaryotes/bacteria- use D and L
  20. ______ immunity involves your bodies direct response to an unknown pathogen. This response is the production of antibodies specific to the antigen of a particular pathogen. ... Conversely, _____ immunity is animmune response which involves antibodies obtained from outside the body.

    infection = ____ , ____ immunity
    vaccination = _____, _____ immunity

    mother to fetus breast milk = __ , __ immunity

    monoclonal antibodies/ immune serum = ____, ____ immunity
    active

    passive

    active , natural

    active, artificial 

    passive, natural

    passive, artifical
  21. ___ immunity is the transfer of active humoral immunity in the form of already made antibodies from one person to another

    ____ immunity involves anatomical barriers, skin, complement, salivary enzymes, neutrophil, NK cells, dendritic cells, monocyte, macrophages, secretory components, movement of intestines, cilia movement, etc

    ____ immunity involves antibodies

    ____ immunity involves t-cells

    ____ immunity involves t cells and b cells antibodies
    passive

    natural/ innate/ nonspecific 

    humoral

    cell-mediated

    adaptive
  22. ____ is composed of short lengths of microtubules arranged in the form of an open ended cylinder designed to help chromosomes separate during cell division
    centriole
  23. _____ is the nuclear subdomain that assembles ribosomal subunits in eukaryotic cells
    nucleolus
  24. 4 functions of smooth ER
    • - lipid synthesis
    • - detox
    • - produce steroid hormones 
    • - carb synthesis
  25. ______ play a major role in the metabolism of very long chain lipids breaking them down into medium chain lipids that are transported to mitochondria for further processing and play a role in detox of ethanol
    peroxisomes
  26. cell differentiation is mediated primarily by ____
    gene expression levels
  27. entropy increases when:

    - moles of substance in system increase (more gas particles)

    - solid or liquid dissolve in solvent 

    - solubility of gas decreases and it escapes solvent

    - when molecular complexity increases (KOH vs Ca(OH)2) due to increased movement of electrons
    entropy increases when:

    - moles of substance in system increase (more gas particles)

    - solid or liquid dissolve in solvent 

    - solubility of gas decreases and it escapes solvent

    - when molecular complexity increases (KOH vs Ca(OH)2) due to increased movement of electrons
  28. ________ is amphipathic (hydrophobic and hydrophilic) and absorbs the air-water-alveoli interface reducing surface tension and total force resisting expansion increasing pulmonary compliance
    pulmonary sufactant
  29. In _______, a bacterium takes up a piece of DNA floating in its environment.

    In _______, DNA is accidentally moved from one bacterium to another by a virus.

    In _______, DNA is transferred between bacteria through a tube between cells.


    _______ are chunks of DNA that "jump" from one place to another. They can move bacterial genes that give bacteria antibiotic resistance or make them disease-causing.
    transformation

    transduction

    conjugation

    Transposable elements
  30. n , l , ml, ms

    n = row on periodic table principle qunatum number. higher principle q numbers n = 2 compared to n = 1 have greater energy and r farther from nucleus

    l = azimuthal angular momentum quantum number 

    S - l = 0
    p - l = 1
    d - l = 2
    f - l = 3


    ml = magnetic quantum number (-l to +l)

    s subshell max electrons = 2
    p subshell max electrons = 6
    d subshell max electrons = 10
    f subshell max electrons = 14

    --------------------

    ms = spin quantum number
    - two electrons in the same orbital and thus with same ml are paired and must have opposite spin +1/2 or -1/2
    n , l , ml, ms

    n = row on periodic table principle qunatum number. higher principle q numbers n = 2 compared to n = 1 have greater energy and r farther from nucleus

    l = azimuthal angular momentum quantum number 

    • S - l = 0
    • p - l = 1
    • d - l = 2
    • f - l = 3


    ml = magnetic quantum number (-l to +l)

    • s subshell max electrons = 2
    • p subshell max electrons = 6
    • d subshell max electrons = 10
    • f subshell max electrons = 14

    --------------------

    • ms = spin quantum number
    • - two electrons in the same orbital and thus with same ml are paired and must have opposite spin +1/2 or -1/2
  31. for light or photon to be emitted an electron must travel from a higher to lower level (n = 4 to n = 2).

    The greater the difference the more likely the emission of photon / light visible to human eye

    ex. from n = 4 to n = 2 

    over n = 2 to n = 1
    for light or photon to be emitted an electron must travel from a higher to lower level (n = 4 to n = 2).

    The greater the difference the more likely the emission of photon / light visible to human eye

    ex. from n = 4 to n = 2 

    over n = 2 to n = 1
  32. _____ are atoms with unpaired valence electrons
    free radicals
  33. Rank in terms of shortest wavelength (highest energy)

    SP, SP3 , SP2

    And why?
    SP > SP2 > SP3

    Cuz SP has the highest S character (50%) compared to SP2 (33%) and SP3 (25%) so it has highest energy cuz electron is hardest to eject
  34. A _____ has same mass as an electron but opposite charge

    An alpha particle has an atomic mass of ___

    a _____ particle is a photon of magnetic energy with no mass
    positron 

    4

    gamma
  35. ____ is the attractive force of an atoms positively charged nucleus on atoms negatively charged valence electrons

    _____ decreases with increasing effective nuclear charge cuz increased protons pulls in the valence electrons closer to nucleus
    Zeff

    effective nuclear charge

    atomic radii
  36. CH4 = Methane
    CH4 = Methane
  37. _____ blank separates proteins of bases of molecular weight/ size alone on electrophoresis
    SDS-Page- which involves the binding of anionic detergent SDS to polypeptide chain . SDS binding denatures and imparts an even distribution of charge per unit mass of protein
  38. More complete fractionation of proteins using size-exclusion chromatography column could be achieved by using a _______
    longer column cuz as all other forms of chromatography increasing column length will enhance the resolution of the column leading to more complete fractionation by size exclusion chromatography. the material on matrix provides a means of separating proteins so proteins come in longer contact with matrix and differences in retarding forces has increased cumulative effect on migrating proteins lengthening the difference in retention times
  39. D vs L =

    R vs S =

    assign priority based off _____

    L amino acids and D carbs predominate
    relative configuration

    absolute configuration

    molecular weight

    L amino acids and D carbs predominate
  40. Stereoisomers = 2^n

    n = # of chiral centers
    Stereoisomers = 2^n

    n = # of chiral centers
  41. Weak acid pH less than PKA

    a pH of 1.0 for an acid whose concentration is 0.10 M would require complete dissociation (strong acid)
    Weak acid pH less than PKA

    a pH of 1.0 for an acid whose concentration is 0.10 M would require complete dissociation (strong acid)
  42. percent yield =
    actual / theoretical x 100
  43. which has higher melting/ boiling point aldehyde and ketones or carboxylic acids and alcohols?
    carboxylic acids and alcohols cuz of hydrogen bonds and can function as organic weak acids
  44. list from highest reactivity to lowest

    anhydride ester thioester amide acid halide
    • acid halide
    • anhydride
    • thioester
    • ester
    • amide
  45. home shopping network QVC
    Q = VC

    • Q = Charge (C)
    • V = Voltage 
    • C = Capacitance (F)
  46. name

    H3PO2 =
    H3PO3 =
    H3PO4 =
    H3PO5 =
    • Hypophosphorous acid
    • Phosphorous acid
    • Phosphoric acid
    • Perphosphoric acid
  47. _____ occurs when a hydronium (H3O+ or H9O4+ Eigen cation) attracts the O on H2O molecules to surround it so a semi-stable shell of water molecules surround it
    hydration (water solvent)

    solvation
  48. ammonia = 
    ammonium =
    • NH3
    • NH4+
  49. volume increase = temp increase
    volume increase = temp increase
  50. ZXC - CXZ = MESO COMPOUNDS
    ZXC - CXZ = MESO COMPOUNDS
  51. The more basic compound has a more stable ________
    conjugate acid
  52. With lactose present (low glucose) it binds to the repressor and the repressor detaches from the operator on the lac operon and RNA Pol can transcribe LacZ, LacY, LacA genes into a single mRNA

    With lactose absent (high glucose) the repressor is bound to operator and RNA Pol cannot move down lac operon and LacZ LacY and LacA genes cannot be transcribed

    negative control- repressor prevents transcription by binding to operator

    positive control - activator stimulates transcription

    negative inducible - repressor normally bound and no transcription takes place until certain conditions take place (Lac operon)

    negative repressible - genes normally transcribed but can be stopped by repressor (trp operon)
    With lactose present (low glucose) it binds to the repressor and the repressor detaches from the operator on the lac operon and RNA Pol can transcribe LacZ, LacY, LacA genes into a single mRNA

    With lactose absent (high glucose) the repressor is bound to operator and RNA Pol cannot move down lac operon and LacZ LacY and LacA genes cannot be transcribed

    negative control- repressor prevents transcription by binding to operator

    positive control - activator stimulates transcription

    negative inducible - repressor normally bound and no transcription takes place until certain conditions take place (Lac operon)

    negative repressible - genes normally transcribed but can be stopped by repressor (trp operon)
  53. ______ and ______ have genome where nearly all material codes for protein
    prokaryotes and unicellular eukaryotes
  54. eukaryotic cilia and flagella are composed of bundles of _______

    prokaryote flagella are composed of ______
    microtubules 

    protein flagellin
  55. microfilaments are composed of ____ and are found in the _____ of eukaryotic cells as well as in _____
    actin

    cytosol

    muscle
  56. _______ is found in the tendons , forms connective ligaments within body, and gives extra support to skin. Its a triple helix formed by 3 proteins wrapped around each other
    collagen
  57. In genetics, a ______ mutation is a point mutationin which a single nucleotide change results in a codon that codes for a different amino acid. It is a type of nonsynonymous substitution.
    missense
  58. ______ mutations are base substitutions that result in no change of the amino acid or amino acid functionality when the altered messenger RNA (mRNA) is translated. For example, if the codon AAA is altered to become AAG, the same amino acid – lysine – will be incorporated into the peptide chain.
    Silent
  59. In genetics, a ______ mutation is a point mutation in a sequence of DNA that results in a premature stop codon,
    point-nonsense
  60. 76kDa vs 40 kDa

    which moves more quickly?

    SDS PAGE 

    SIZE EXCLUSION CHROMATOGRAPHY
    SDS PAGE - 40 kDa move more quickly

    SEC - 76kDa
  61. in absence of oxygen pyruvate is fermanted into _______ in the cytoplasm and doesn't go to mitochondria to be converted to acetyl CoA therefore krebs cycle products like citrate won't have high concentration
    lactate
  62. _______ is failure of chromosomes to separate during anaphase 1 of meiosis or failure of sister chromatids to separate during anaphase 2 of meiosis
    nondisjunction
  63. in acid dissociation reactions H+ is a product and so according to le chantlies principle if you remove product you have shift to product so if u remove H+ acetic acid will dissociate more
    in acid dissociation reactions H+ is a product and so according to le chantlies principle if you remove product you have shift to product so if u remove H+ acetic acid will dissociate more
  64. for there to be an enol tautomer there needs to be a H+ to abstract from the alpha carbon adjacent to the carbonyl to a double bond can occur and you can go from keto to enol form and H goes to O for OH
    for there to be an enol tautomer there needs to be a H+ to abstract from the alpha carbon adjacent to the carbonyl to a double bond can occur and you can go from keto to enol form and H goes to O for OH
  65. which enzyme has a higher binding affinity for its substrate?

    A- Kd (dissociation constant) = 10
    B- Kd = 1
    enzyme B because lower dissociation constant means higher binding affinity for its substrate because lower Kd means it doesn't readily dissociate from ES Complex into enzyme and substrate therefore its more stable
  66. citric acid cycle activity is positively correlated with vascularization because of increased need for oxygen supply (oxidative metabolism) and waste removal where there is high citric acid cycle activity
    citric acid cycle activity is positively correlated with vascularization because of increased need for oxygen supply (oxidative metabolism) and waste removal where there is high citric acid cycle activity
  67. HBr - hydrobromic acid
    HI- hydroiodic acid
    HCl- hydrochloric acid
    HNO3 - nitric acid
    H2SO4 - sulfuric acid
    HClO4 - perchloric acid 

    CsOH - Cesium hydroxide
    KOH- Potassium hydroxide
    LiOH - Lithium hydroxide
    NaOH- Sodium hydroxide
    strong acids and bases
  68. _______ reducing agent often used during SDS-PAGE to further denature proteins by reducing/ cleaving disulfide linkages and breaking up quaternary protein structure (oligomeric subunits).

    one band present when not exposed to DTT and 3 bands when exposed shows at least two disulfide linkages present in molecule and these linkages hold 3 separate subunits together
    _______ reducing agent often used during SDS-PAGE to further denature proteins by reducing/ cleaving disulfide linkages and breaking up quaternary protein structure (oligomeric subunits).

    one band present when not exposed to DTT and 3 bands when exposed shows at least two disulfide linkages present in molecule and these linkages hold 3 separate subunits together
  69. kidneys response to alcohol similar to its response to low blood osmolarity and high blood pressure

    alcohol lowers adh so more water in kidney less water reabsorbed and less water in blood stream and more water excreted in urine. 

    this is similar to kidneys response to high blood pressure and low blood osmolarity which makes water less likely to be reabsorbed by kidneys so more excreted and lower blood volume and pressure
    kidneys response to alcohol similar to its response to low blood osmolarity and high blood pressure

    alcohol lowers adh so more water in kidney less water reabsorbed and less water in blood stream and more water excreted in urine. 

    this is similar to kidneys response to high blood pressure and low blood osmolarity which makes water less likely to be reabsorbed by kidneys so more excreted and lower blood volume and pressure
  70. Histone acetylation and deacetylation are the processes by which the lysine residues within the N-terminal tail protruding from the histone core of the nucleosome are acetylated and deacetylated as part of gene regulation.

    Acetylated histones, octameric proteins that organize chromatin into nucleosomes and ultimately higher order structures, represent a type of epigenetic marker within chromatin. Acetylation removes the positive charge on the histones, thereby decreasing the interaction of the N termini of histones with the negatively charged phosphate groups of DNA. As a consequence, the condensed chromatin is transformed into a more relaxed structure that is associated with greater levels of gene transcription.
    Histone acetylation and deacetylation are the processes by which the lysine residues within the N-terminal tail protruding from the histone core of the nucleosome are acetylated and deacetylated as part of gene regulation.

    Acetylated histones, octameric proteins that organize chromatin into nucleosomes and ultimately higher order structures, represent a type of epigenetic marker within chromatin. Acetylation removes the positive charge on the histones, thereby decreasing the interaction of the N termini of histones with the negatively charged phosphate groups of DNA. As a consequence, the condensed chromatin is transformed into a more relaxed structure that is associated with greater levels of gene transcription.
Author
JAM41MAN
ID
340626
Card Set
mcat science 2
Description
science
Updated