Cards (24)

  • What are the monomers from which proteins are made?
    Amino acids
  • What groups do amino acids contain?
    Amino group, carboxylic acid group, R group
  • How many different amino acids are there?
    20
  • What type of bond joins amino acids?
    Peptide bonds
  • What is formed during the condensation reaction of amino acids?

    A molecule of water
  • What is a dipeptide?

    A molecule containing two amino acids
  • What are polypeptides?

    Molecules containing three or more amino acids
  • What determines the structure of proteins?
    • Order and number of amino acids
    • Types of bonding present
    • Shape of the protein
  • What is the primary structure of a protein?
    The order and number of amino acids
  • How does the primary structure affect protein function?
    It determines the protein's function
  • What shapes can the secondary structure of proteins take?
    Alpha helix or beta pleated sheet
  • What causes the formation of hydrogen bonds in proteins?
    Charge differences in -NH and -C=O groups
  • What is the tertiary structure of proteins?
    The 3D shape formed by folding
  • What types of bonds maintain the tertiary structure of proteins?

    Disulfide bridges, ionic bonds, hydrogen bonds
  • What are disulfide bridges?
    Interactions between sulfur in cysteine
  • How do ionic bonds form in proteins?
    Between carboxyl and amino groups
  • Why are ionic bonds considered weaker than disulfide bridges?
    They are easily broken by pH
  • What characterizes globular proteins?

    They are compact in structure
  • What is an example of a fibrous protein?
    Keratin
  • What is the Biuret test used for?
    • Tests for presence of peptide bonds
    • Detects proteins in food
  • What is the first step of the Biuret test?
    Add sodium hydroxide to the sample
  • What is added after sodium hydroxide in the Biuret test?

    Dilute copper (II) sulfate solution
  • What indicates a positive result in the Biuret test?

    A purple coloration
  • What does a negative result in the Biuret test look like?
    The solution remains blue