proteins

• What is the primary structure of a protein?

  The sequence of amino acids bonded by peptide bonds
• How does DNA influence the primary structure of a protein?

  It instructs the cell to add amino acids in sequence
• What can happen if there is one alteration in the amino acid sequence?

  It can affect the function of the protein
• What type of bonds form the secondary structure of a protein?

  Hydrogen bonds
• What are the two shapes that can form in the secondary structure of proteins?

  a-helix and b-pleated sheet
• How does the α-helix shape form?

  Hydrogen bonds form between every fourth peptide bond
• How does the β-pleated sheet shape form?

  Two parts of the polypeptide chain are parallel
• What does the secondary structure relate to?

  Hydrogen bonds between the amino and carboxyl groups
• What can break hydrogen bonds in proteins?

  High temperatures and pH changes
• What leads to the tertiary structure of a protein?

  Further conformational change of the secondary structure
• What types of bonds form in the tertiary structure?

  Hydrogen, disulphide, ionic, and hydrophobic interactions
• Which proteins commonly have secondary structures?

  Fibrous proteins like collagen and keratin
• What are disulphide bonds?

  Strong covalent bonds between cysteine R groups
• Why are disulphide bonds important in proteins?

  They help stabilize the protein structure
• What can break disulphide bonds?

  Oxidation
• Where are ionic bonds formed in proteins?

  Between positively and negatively charged R groups
• How do ionic bonds compare to hydrogen bonds?

  Ionic bonds are stronger but less common
• What types of R groups form hydrogen bonds?

  Strongly polar R groups
• What are hydrophobic interactions?

  Interactions between non-polar R groups in proteins
• How does tertiary structure determine protein function?

  It affects how the polypeptide chain folds
• How many unique R groups are there among amino acids?

  Twenty
• What is quaternary structure in proteins?

  Structure with more than one polypeptide chain
• What is each polypeptide chain in quaternary structure called?

  A subunit of the protein