Carbohydrates and Proteins Pack 1

  1. What is a monomer?
    Smaller units from which larger molecules are made up of
  2. What is a polymer?
    Polymers are molecules made from a large number of monomers joined together
  3. What is an example of a monomer?
    • Any of the three;
    • Monosaccharides
    • Amino acids
    • Nucleotides
  4. What is a condensation reaction?
    A condensation reaction is one which joins two molecules together with the formation of a chemical bond and involves elimination of a water molecule.
  5. What is a hydrolysis reaction?
    A hydrolysis reaction is one which breaks a chemical bond between two molecules and involves the use of a water molecule.
  6. Glucose, galactose and fructose are examples of what?
    Monomers (of which larger carbohydrates are made up of)
  7. What do monomers join together to form?
  8. What process joins monomers together?
    Condensation Reactions
  9. What are polymers broken down into?
  10. What breaks down polymers into monomers?
    Hydrolysis reactions
  11. What elements do proteins contain?
    • Carbon
    • Hydrogen
    • Oxygen
    • Nitrogen
  12. What is a protein made up from?
    Proteins are polymers made up of one or more chains of amino acid monomers known as polypeptides.
  13. What are amino acids made up from? (3)
    • An amino group
    • a carboxylic group
    • A Variable group
  14. What makes an amino acid unique?
    The R group/variable group
  15. What does the variable group affect on an amino acid?
    It's properties it has
  16. Two amino acids join together to form what?
  17. What is the bond between the amino acids called?
    peptide bond(s)
  18. What is a peptide bond?
    a strong covalent bond
  19. What is the general structure of an amino acid?
    Image Upload 1

    Amino group ; R Group ; carboxylic acid group
  20. Many amino acids link together by condensation to form what?
    a polypeptide chain
  21. What are the four levels of protein structure?
    • 1. Primary structure
    • 2. Secondary Structure
    • 3. Tertiary Structure
    • 4. Quaternary Structure
  22. What is the primary structure of a protein?
    This is the sequence of amino acids in a polypeptide chain

    (amino chain)
  23. What is the secondary structure of a protein?
    This is further folding of the polypeptide chain. As they fold they allow the formation of weak H-bonds which produce particular secondary structures

    (hydrogen bonds between amino acids)
  24. Give two examples of secondary structures.
    • a-helix
    • B-pleated sheet
  25. Where would you find alpha helical structures of proteins?
    fibrous proteins such as keratin (hair and nails)
  26. Where would you find B-pleated sheets?
    globular proteins such as enzymes
  27. What is the tertiary structure of a protein?
    further folding where the whole chain (including secondary structures) folds into a specific shape. 

    It is stabilised by ionic bonds, hydrogen bonds and disulphide bonds.

    (alpha helix and beta-pleated sheets attract)
  28. What is a disulphide bond?
    A covalent bond between sulphur-containing amino acids
  29. What can cause a protein to become denatured?
    high temperatures and extremes of pH
  30. How does a protein become denatured?
    Hydrogen bonds break first, as they are very weak bonds. The disulphide bonds are stronger and can withstand higher temperatures.
  31. What happens when the bonds break in a protein?
    When the bonds break, the tertiary structure is lost and the protein loses its function.
  32. What is it that determines the function of a protein?
    The specific shape of the tertiary structure of the protein
  33. What is the quaternary structure of a protein?
    This is found in proteins made up of more than one polypeptide chain -----> 2 alpha chains or 2 beta chains

    (more than one chain joined together)
  34. What are the different shapes of proteins?
    Fibrous and globular
  35. What are fibrous proteins?
    These form long chains running parallel to each other with cross-bridges between the chains. This produces very stable molecules.
  36. What is collagen?
    Collagen is a protein found in tendons which join muscle to bone
  37. Describe Collagen's primary structure?
    unbranched polypeptide chain
  38. Describe Collagen's secondary structure?
    the polypeptide chain forms an a-helix. 

    lots of amino acid glycine helps close packaging
  39. What is the tertiary structure of collagen?
    the polypeptide chain is further twisted
  40. What is the quaternary structure of collagen?
    3 polypeptide chains are wound together with covalent bonds between amino acids of adjacent chains
  41. Why does the quaternary structure of collagen make it a suitable molecule for a tendon?
    • Collagen is found in tendons which join muscle to bone.
    • Tendons need to be very strong and not elastic.
    • Cross-links between adjacent polypeptide chains in the fibres proved strength and stability.
    • The points where one collagen molecule ends and another one starts are spread throughout the fibres, rather than being at the same point
  42. Give two examples of globular proteins
    Enzymes and haemoglobin
  43. What do globular proteins carry out?
    metabolic functions
  44. What is the Biuret test for proteins?
    • add potassium hydroxide and copper sulphate (buret solution) to a sample of the solution to be tested
    • if the solution turns lilac then a protein is present
    • if the sample does not contain protein, only the pale blue colouration of the copper sulphate is seen
  45. What elements are carbohydrates composed of?
    carbon, hydrogen and oxygen
  46. What are monosaccharides?
    basic molecular units/monomers of which other carbohydrates are composed
  47. Give three examples of carbohydrates
    glucose, galactose and fructose
  48. What properties do monosaccharides have?
    soluble and sweet
  49. What type of sugar is glucose?
  50. What is meant by a hexose sugar?
    It contains 6 carbon atoms
  51. What is the formula of glucose?
  52. What is the formula of a pentose sugar?
  53. What is the formula of a triose sugar?
  54. What is glucose a product of?
  55. What is glucose a major substate of?
  56. What does the term 'isomers' mean?
    different structural form
  57. what are the different forms/isomers of glucose?
    a-glucose and B-glucose
  58. What is the difference between a-glucose and B-glucose?
    The hydroxyl group points down in a-glucose and points upwards in B-glucose
  59. What is a disaccharide?
Card Set
Carbohydrates and Proteins Pack 1
aqa biology flashcards