Proteins

• What are enzymes?

  Soluble, spherical proteins that catalyze reactions
• How do enzymes function?

  They catalyze metabolic reactions
• What does lipase digest?

  It digests lipids
• What are antibodies and their function?

  • Produced by plasma cells
  • Function in immune response
  • Bind to specific antigens
  • Help fight infections
• What is the role of structural proteins?

  Provide strength and support
• What do structural proteins consist of?

  Long polypeptide chains twisted into shapes
• What are transport proteins and how do they function?

  • Found in cell membranes
  • Form channels or carriers
  • Move substances across membranes
  • Have hydrophobic and hydrophilic regions
• What is the Biuret test for proteins?

  A test using sodium hydroxide and copper sulfate
• What indicates the presence of protein in the Biuret test?

  A purple color change
• What happens if no protein is present in the Biuret test?

  The solution remains blue
• How does the Biuret test work?

  Add sodium hydroxide and copper sulfate
• What does a color change from blue to purple indicate in the Biuret test?

  Presence of protein in the solution
• What is the first step in the Biuret test?

  Add sodium hydroxide to make it alkaline
• What is the significance of the color change in the Biuret test?

  It indicates the presence of protein
• How is the color change in the Biuret test described?

  Subtle change from blue to purple
• What are the building blocks of proteins?

  Amino acids
• How many different amino acids are there?

  20 different amino acids
• What is a peptide bond?

  A bond formed between two amino acids
• What happens during a hydrolysis reaction?

  A peptide bond is broken by water
• What determines the primary structure of a protein?

  The sequence of amino acids in the chain
• What bonds are responsible for the secondary structure of a protein?

  Hydrogen bonds
• What is quaternary structure?

  Structure formed by multiple polypeptide chains
• What type of bond holds amino acids together in a polypeptide chain?

  Peptide bonds
• What role do disulfide bridges play in proteins?

  They stabilize the tertiary structure