proteins

• What are proteins made up of?

  Amino acids
• What is another name for a polypeptide?

  Protein
• What groups do all amino acids contain?

  Carboxyl, amino, and variable (R) groups
• How many different amino acids are there?

  20
• What changes the properties of an amino acid?

  The variable (R) group
• How are adjacent amino acids joined together?

  By peptide bonds
• What type of bond is a peptide bond?

  Covalent bond
• How is a dipeptide formed?

  Two amino acids join during condensation
• What are the four levels of protein structure?

  • Primary
  • Secondary
  • Tertiary
  • Quaternary
• What defines the primary structure of a protein?

  The order of amino acids in a polypeptide
• What forms the secondary structure of proteins?

  Hydrogen bonds between amino acids
• What are the two forms of secondary structure?

  α-helix and β-pleated sheet
• What is a hydrogen bond?

  A weak electrostatic attraction
• What is the tertiary structure of a protein?

  The final 3D structure of a polypeptide
• What causes the tertiary structure to form?

  1. group interactions
• What types of interactions are involved in tertiary structure?

  Hydrogen bonds, ionic bonds, disulfide bridges
• What can affect a protein's function?

  Changes in tertiary or quaternary structure
• What genetic disease is caused by a mutation in haemoglobin?

  Sickle cell disease
• What is the quaternary structure of a protein?

  The joining of multiple polypeptides
• What amino acid is swapped in sickle cell disease?

  Glutamine is swapped for valine
• What change occurs in the primary structure due to mutation?

  A change in the sequence of amino acids
• How does the mutation affect the tertiary structure?

  It alters R-group interactions
• What is the food test for proteins called?

  Biuret test
• What is the procedure for the Biuret test?

  Add NaOH and dilute CuSO₄
• What color indicates the presence of proteins in the Biuret test?

  Blue to purple
• What are the learning outcomes related to proteins?

  • Describe the structure of an amino acid
  • Describe the different levels of protein structure
  • Explain how protein structures relate to their functions
  • Describe the biochemical test for proteins