Chemistry-chapter 14-proteins.txt

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HeidiG
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117936
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Chemistry-chapter 14-proteins.txt
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2011-11-19 17:40:29
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Organic Biological Chemistry Chapter 14 Proteins
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Flash cards for Organic and Biological Chemistry Chapter 14: proteins
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    • author "Heidi"
    • tags "chemistry"
    • description "Keywords and concepts from chapter 14 of chemistry"
    • fileName "Chemistry-chapter 14-proteins"
    • freezingBlueDBID -1.0
    • What are the 8 functions of proteins?
    • Structure
    • Catalysis - virtually all the reactions that take place in the living organisms are catalyzed by proteins called enzymes
    • Movement - muscles are made up of proteins called myosin and actin
    • Transport
    • Hormones
    • Protection
    • Storage
    • Regulation
  1. What are two important stuctural proteins?
    Collagen and keratin
  2. What type of proteins catalyze reactions?
    Enzymes
  3. What two proteins make up muscles?
    Myosin and actin
  4. Name three hormones made up of proteins.
    Insulin erythropoietin and human growth hormone
  5. What is a protein from an outside source or any other foreing substance called?
    Antigen
  6. What are the proteins that the body makes to fight antigens called?
    Antibodies
  7. What are the two main things that proteins regulate?
    Gene expression (thereby regulating what proteins get synthesized in each cell) and when proteins get produced.
  8. What are the two major types of proteins?
    Fibrous proteins and globular proteins
  9. Are fibrous proteins soluble in water?
    No
  10. What are fibrous proteins mainly used for?
    Stuctural purposes
  11. Are globular proteins soluble in water?
    More or less (yes)
  12. What are globular proteins mainly used for?
    Nonstructural purposes
  13. What are amino acids?
    An organic compound containing an amino group and a carboxyl group.
  14. What is an alpha amino acid?
    An amino acid in which the amino group is linked to the carbon atom next to the -COOH carbon.
  15. What are the four groups of amino acids?
    • Nonpolar
    • Polar but neutral
    • Acidic
    • Basic
  16. Which group (or groups) of amino acids are hydrophobic?
    The nonpolar amino acids
  17. Which group (or groups) of amino acids are hydrophilic?
    The polar but neutral acidic and basic amino acids
  18. Which amino acids are nonpolar (hydrophobic)?
    Leucine, proline, alanine, valine,methionine, tryptophan, phenylalanine, and isoleucine.
  19. How many nonpolar amino acids are there?
    Eight
  20. How many polar but neutral amino acids are there?
    Seven
  21. What are the polar but neutral amino acids?
    Glycine, serine, asparagine, glutamin, theronine, cysteine, and tyrosine.
  22. How many acidic amino acids are there?
    Two
  23. What are the acidic amino acids?
    Aspartic acid, and glutamic acid
  24. How many basic amino acids are there?
    Three
  25. What are the basic amino acids?
    Histadine, lysine, and arginine.
  26. Which of the twenty amino acids is achiral?
    Glycine
  27. Which enantomer of amino acids is found in the body?
    All of the proteins in your body (except for glycine, which is achiral) are the L-isomers.
  28. What are zwitterions?
    Compounds that have a positive charge on one atom and a negative charge on another.
  29. Are amino acids zwitterions in both water solutions and the solid state?
    Yes
  30. Are amino acids ionic compounds?
    Yes
  31. Are all amino acids solids with high melting points?
    Yes
  32. Are all twenty common amino acids fairly soluble in water?
    Yes.
  33. What happens to a zwitterion (such as an amino acid) in a solution with a low pH?
    The zwitterion becomes a positive ion.
  34. What happens to a zwitterion in a solution that has a high pH?
    The zwitterion becomes a negative ion.
  35. What is an isoelectric point?
    A pH at which a sample of amino acids or proteins has an equal number of positive and negative charges.
  36. How many of the twenty common amino acids have isoelectric points near six?
    Fifteen
  37. What is an amphiprotic compound?
    A compound that is both an acid and a base.
  38. What is a buffer solution?
    A solution that neutralizes both acid and base.
  39. Are amino acid amphiprotic compounds?
    Yes
  40. Are amino acids buffers?
    Yes, aqueous solutions of them are buffers.
  41. What determines the functions of amino acids, and their polymers, and proteins?
    The side chains of the amino acids.
  42. What amino acid has a chemical property not shared by any of the others?
    What is the chemical property?
    • The amino acid is cysteine.
    • The chemical property is that it can be dimerized by many mild oxidizing agents.
    • The dimer of cysteine is called cystine. Cystine, can be fairly easily reduced to give two molecules of cysteine.
  43. What is the bond between two amino acids(that contain sulfur) called?
    A disulfied bond.
  44. Which three amino acids have basic side chains?
    Histidine, lysine, and arginine.
  45. Which amino acids have aromatic rings in there side chains?
    Tryptophan, phenylalanine, and tyrosine.
  46. Which amino acid is converted to serotonin?
    Tryptophan
  47. Which amino acid is found in artificial sweeteners?
    Phenylalanine
  48. Which amino acid has been known to make people sleepy?
    Tryptophan
  49. Which amino acid has been known to give some people a "morning lift"?
    Tyrosine
  50. What are the twenty common amino acids?
    Alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, and valine.
  51. What two functional groups on amino acids are combined?
    The carboxylic acid on one amino acid bonds to the amino group of the second amino acid and forms an amide.
  52. What type of bond is formed between two animo acids?
    A peptide bond.
  53. What is the product of two amino acids being bonded together?
    Dipeptide
  54. Can you add three amino acids together?
    If yes what is the product?
    Yes, the product is a tripeptide.
  55. What are peptides?
    The shortest chain of amino acids.
  56. What are polypeptides?
    Long chains of amino acids.
  57. What are proteins?
    • Even longer chains of amino acids.
    • A chain that contains at least 30-50 amino acids.
  58. What are amino acids in a chain often called?
    Residues
  59. What is the c-terminus?
    The amino acid at the end of a peptide that has a free alpha carboxyl group.
  60. What is the n-terminus?
    The amino acid at the end of a peptide that has a free alpha amino group.
  61. Which side is the n-terminus written on?
    The n-terminus is always written on the left.
  62. Is there freedom of rotation about the two bonds from the alpha carbon?
    Yes
  63. Is there freedom of rotation of the carbon nitrogen bond?
    No
  64. When are proteins least soluble in water?
    At there isoelectric points.
  65. When can proteins be precipitated from their solutions?
    At their isoelectric points.
  66. What are the four levels of organization in protein structure?
    Primary structure, secondary structure, tertiary structure, and quaternary structure.
  67. What is primary structure?
    The sequence of amino acids in a protein.
  68. What is secondary structure?
    A repetitive conformation of the protein backbone.
  69. What are the two most common secondary structures?
    Beta pleated sheet, and alpha helix
  70. What are random coils?
    Those protein conformations that do not exhibit a repeated pattern.
  71. Describe the alpha helix.
    A secondary structure where the protein folds into a coil held together by hydrogen bonds parallel to the axis of the coil.
  72. Describe the beta pleated sheet.
    A secondary protein structure in which the backbone of two different molecules is held together by hydrogen bonds.
  73. What is tertiary structure?
    The complete three dimensional arrangemant of the atoms in a protein.
  74. What are the five ways tertiary proteins are stabilized?
    • Covalent bonds
    • Hydrogen bonding
    • Salt bridges
    • Hydrophobic interactions
    • Metal ion coordination
  75. Which type of covalent bond is most often involved in stabilizing tertiary structure?
    Disulfide bonds
  76. What is a chaperone?
    A protein that helps other proteins to fold into the biologically active conformation and enables partially denatured proteins to regain their biologically active conformation.
  77. What is the quaternary structure?
    The spatial relationship and interactions between subunits in a protein that has more than one polypeptide chain.
  78. What are conjugated proteins?
    Proteins that contain non-amino acids portions
  79. What is a prosthetic group?
    The non-amino acid portion of a conjugated protein.
  80. What is the structure of hemoglobin?
    Hemoglobin is made up of four chains two identical chains of 141 amino acid residues each and two identical beta chains 146 residues each.
  81. An estimated one third of all proteins are...?
    Integral membrane proteins.
  82. What is denaturation?
    The loss of the secondary, tertiary, and quaternary structures of a protein by a chemical or physical agent that leaves the primary intact.

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