Biology 1115 Chapter 5

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Biology 1115 Chapter 5
2013-10-10 03:13:25
biological molecules

The structure and function of large biological molecules
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  1. What are the four classes of large biological molecules?
    • carbohydrates
    • lipids
    • proteins
    • nucleic acid
  2. What are macromolecules? (2)
    Are large molecules composed of thousands of covalently connected atoms. They are polymers built from monomers.
  3. Molecular _______ and ________ are inseparable.
    Structure and function
  4. Define polymer.
    A polymer is a long molecule consisting of many similar building blocks.
  5. Define monomer.
    These are the small building block molecules that make up polymers.
  6. What are the 3 out of 4 classes of life's organic molecules that are polymers?
    • carbohydrates
    • proteins
    • nucleic acid
  7. What happens in a dehydration reaction?
    A dehydration reaction (condensation reaction) occurs when two monomers bond together through the loss of water molecules.
  8. What is hydrolysis reaction? (2)
    • Polymers are dissembled to monomers by hydrolysis, a reaction that is essentially the reverse of dehydration reaction,
    • adds water molecules, breaking a bond
  9. What is the basis for such diversity in these macromolecules?
    different combinations
  10. Define carbohydrates.
    Carbohydrates include sugars and the polymers of sugars.
  11. What is a monosaccharide?
    • The simplest carbohydrates or single sugars
    • monomer of carbohydrates
  12. What is a polysaccharide?
    • carbohydrate macromolecule
    • polymers composed of many sugar building blocks
  13. What are the 3 major functions of carbohydrates?
    • energy/storing energy
    • serve as fuel
    • building material
  14. Carbohydrates are typically made from which elements?
    hydrogen, carbon, oxygen
  15. What is the standard molecular formula for carbohydrates?
  16. What is the most common monosaccharide and what is its chemical formula?
    Glucose (C6H12O6)
  17. What are the 2 functions of monosaccharides?
    • serves as major fuel source for cells
    • serve as raw material for building molecules
  18. How are monosaccharides classified? (2)
    • the number of carbons in the carbon skeleton
    • the location of the carbonyl group
  19. What is a carbonyl group?
    Carbon double bonded to oxygen
  20. What is the difference between aldose and ketose?
    • The location of the carbonyl group.
    • Ketose: if carbonyl group in the middle
    • Aldose: if carbonyl group is at the end
  21. What is the difference between glucose and galactose?
    They are enantiomers.
  22. Many sugars form________.
    rings (know how to draw glucose ring.)
  23. Define disaccharide.
    It's formed when a dehydration reaction joins two monosaccharides.
  24. What is the bond between disaccharides (carbohydrates) called?
    This covalent bond is called a glycosidic linkage.
  25. Define polysaccharide. what are it's roles?
    • The polymers of sugars.
    • have storage and structural roles
  26. How is the structure and function of a polysaccharide determined?
    It's determined by it's sugar monomers and positions of glycosidic linkages.
  27. What are the four important polysaccharides?
    • starch: plant storage
    • glycogen: animal storage
    • cellulose: structural role in plants
    • Chitin: found on insects and bacteria
  28. Define starch.
    a storage polysaccharide of plants, consists entirely of glucose monomers.
  29. Define glycogen. what is the difference between glycogen and starch?
    • is a storage polysaccharide in animals, glucose monomers
    • more compact and branched than starch.
  30. Where do humans and other vertebrates store glycogen?
    mainly in liver and muscle cells.
  31. Define cellulose. How is it different from starch?
    • is major component of the tough wall of plant cells; glucose monomer
    • glycosidic linkages differ. The difference is based on two ring forms of glucose, alpha and beta
    • (linkages are at the top)
  32. Polymers with a alpha glucose are ______.
  33. Polymers with beta glucose are _________.
    straight, which is better for structural polymer
  34. Define Chitin.
    • structural polysaccharide, is found in the exoskeleton of arthropods
    • also provides structural support for the cell walls of many fungi
  35. Lipids are typically made from which elements? How does this differ from carbohydrates?
    Carbon, hydrogen, and oxygen. Lipids have less oxygen than carbohydrates.
  36. What are lipids? (2)
    • -are the one class of large biological molecules that do not form polymers
    • -have little or no affinity for water

  37. Lipids are __________ because the consist mostly of __________. Why does this occur?
    • hydrophobic, hydrocarbons
    • hydrocarbons are hydrophilic because they have nonpolar covalent bonds.
  38. What are the 3 most important biological lipids?
    • fats
    • phospholipids
    • steroids
  39. Define fats.
    They're constructed from glycerol and fatty acids
  40. How are triglycerides formed?
    three fatty acids are joined to glycerol by an ester linkage
  41. What is the difference between saturated and unsaturated fats?
    • Saturated fatty acids: have the maximum number of hydrogen atoms possible and no double bonds
    • Unsaturated fatty acids: have one or more double bonds.
  42. What is the difference between saturated and unsaturated fats regarding their state at room temperature?
    • Saturated fats: solid at room temperature; most animal fats are saturated
    • Unsaturated fats: liquid at room temperature; most plants and fish fats are unsaturated.
  43. What are trans fats? (2)
    • They have double bonds
    • trans isomers
  44. what are 4 functions of fat in the body?
    • storage
    • energy
    • insulation
    • cushioning and protection of organs
  45. What is the structure of a phospholipid?
    two fatty acids and a phosphate group are attached to glycerol.
  46. What do phospholipids usually have? (3)
    • They usually have one saturated fatty acid tail and one unsaturated fatty acid tail.
    • phosphate group has a negative charge
    • hydrophilic head and hydrophobic tails
  47. Define steroids. Give an example.
    • are lipids characterized by a carbon skeleton consisting of four fused rings
    • cholesterol is an example; it's the building block for different hormones
  48. What is the general term for monomers of protein?
    Amino acids
  49. What is the general term for polymers of protein?
  50. Proteins are typically made from what elements?
    • carbon, hydrogen, oxygen, nitrogen,
    • some sulfur
  51. What are some functions of proteins? (8)
    • coordinate organism activities
    • response of cell to chemical stimuli
    • acceleration of chemical reactions
    • protection against disease
    • movement
    • support
    • storage of amino acids
    • transport of substances
  52. What are enzymes?
    are a type of protein that acts as a catalyst to speed up chemical reactions.
  53. What are amino acids? (2) (know how to draw)
    • are organic molecules with a carboxyl group and an amino group.
    • carboxyl group acts as an acid and amino group acts as a base; both give polarity
  54. All polypeptides are polymers constructed from the same set of _________.
    20 amino acids
  55. What are the 4 categories of amino acids and their distinction?
    • Non-polar side chains (hydrophobic): hydrocarbons
    • Polar side chains (hydrophilic):
    • Acidic negatively charged (hydrophilic side chains): carboxyl group
    • Basic positively charged (hydrophobic side chains): amino group
  56. Amino acids are linked by __________.
    Peptide bonds.
  57. What are the four levels of protein structure?
    • Primary structure: sequence of amino acids
    • Secondary structure: coils (alpha helix) and folds (beta pleated sheets)between polypeptide backbone resulting from hydrogen bonding
    • Tertiary structure: determined by interactions between R-Groups
    • Quaternary structure: when two or more polypeptide chains form one macromolecule.
  58. What are the interactions between R-groups in the tertiary structure? (4)
    • hydrogen bonds
    • ionic bonds
    • hydrophobic interactions
    • Van der Waals interactions
  59. Strong covalent bonds called __________ may reinforce the protein structure in the tertiary structure of proteins.
    Disulfide bridges.
  60. Define Collagen and hemoglobin.
    Collagen is a fibrous protein and hemoglobin is a globular protein.
  61. What are some physical and chemical conditions that can affect the proteins structure? (4)
    • alteration in pH
    • salt concentration
    • temperature
    • other environmental factors
  62. The loss of a protein's native structure is called ________.
  63. What are chaperonins?
    They are protein molecules that assist the proper folding of other proteins.
  64. What is the general term for monomers of nucleic acid?
  65. what is the general term for polymers of nucleic acids?
  66. Nucleic acids are typically made from which elements? (5)
    carbon, oxygen, hydrogen, nitrogen, phosphorous.
  67. List the major types of nucleic acid. (3)
    • DNA
    • RNA
    • ATP
  68. What major functions do nucleic acids perform?
    Forming proteins
  69. List the 3 major types of RNA and function.
    • mRNA (messenger RNA): transfers replicated RNA to the ribosome
    • tRNA (transfer RNA): builds the polypeptide chain by organizing the order of amino acids
    • rRNA (ribosomal RNA): does functions for the ribosome.
  70. What does a nucleotide include?
    • consists of a nitrogenous base
    • pentose sugar
    • phosphate group
  71. what does nucleoside include?
    • nitrogenous base
    • pentose sugar
  72. What are the two families if nitrogenous bases and what do they include?
    • Pyrimidine: have a single six-membrane ring; includes cytosine, thymine and uracil
    • Purine: have six-membrane ring fused to a five-membrane ring; includes adenine and guanine
  73. What is the difference in sugars between DNA and RNA?
    • DNA: deoxyribose
    • RNA: ribose
  74. Nucleotide monomers are linked together to build a polynucleotides by what linkage?
    phosphodiester linkages
  75. What are the base pairing in DNA?
    • Cytosine and guanine: 3 hydrogen bonds
    • adenine and thymine: 2 hydrogen bonds (uracil replaces thymine)
  76. What are 3 differences between DNA and RNA?
    • DNA: double helix, deoxyribose, thymine
    • RNA: single strand, ribose, uracil