18.2.2 Proteins

• What type of bonds link amino acids together in proteins?

  Peptide bonds
• Amino acids are the monomers
• Match the key component of an amino acid with its chemical formula:

  Amino group ↔️ -NH₂

  Carboxyl group ↔️ -COOH
• The amino group of an amino acid is acidic.

  False
• What is the general term for a molecule composed of amino acids linked by peptide bonds?

  Protein
• Arrange the components of an amino acid in the correct order of their significance:

  1️⃣ Amino group

  2️⃣ Carboxyl group

  3️⃣ R group

  4️⃣ Alpha carbon
• The R group of an amino acid determines its specific properties
• What type of reaction forms a peptide bond between two amino acids?

  Condensation reaction
• The peptide bond is a rigid and planar C-N bond due to a partial double bond between carbon and nitrogen
• A polypeptide is a long chain of amino acids joined by covalent bonds.
• Match the key concept with its description:

  Peptide Bond ↔️ Covalent bond linking amino acids

  Condensation Reaction ↔️ Forms peptide bond with release of water

  Polypeptide ↔️ Long chain of amino acids
• Which group in an amino acid dictates its properties?

  R group
• The R group of an amino acid dictates its specific properties
• The formation of a peptide bond releases a molecule of water.
• Match the key concept with its description:

  Peptide Bond ↔️ Covalent bond linking amino acids

  Condensation Reaction ↔️ Forms peptide bond with release of water

  Polypeptide ↔️ Long chain of amino acids
• What type of bond links amino acids together in a polypeptide chain?

  Peptide bond
• Peptide bonds are formed through a condensation reaction.
• Peptide bonds release a water molecule during their formation.
• Which two functional groups of amino acids react to form a peptide bond?

  Carboxyl and amino groups
• Peptide bonds are C-N bonds with a partial double bond character, making them rigid and planar.
• What does the primary structure of a protein describe?

  Sequence of amino acids
• The primary structure of a protein is determined by peptide bonds.
• What chemical reaction releases water when a peptide bond is formed?

  Condensation reaction
• Steps involved in forming protein secondary structure

  1️⃣ Primary structure: Amino acid sequence

  2️⃣ Secondary structure: Local folding patterns

  3️⃣ Alpha helix or beta sheet formation
• Hydrogen bonds are crucial for maintaining the stability of protein secondary structure.
• What type of hydrogen bonds stabilize the alpha helix in secondary structure?

  Carbonyl oxygen and amide hydrogen
• Beta sheets in proteins can be parallel or antiparallel.
• What stabilizes beta sheets in secondary protein structure?

  Hydrogen bonds
• Hydrogen bonding in proteins involves the attraction between carbonyl oxygen and amide hydrogen
• What is the secondary structure of a protein defined by?

  Hydrogen bonds
• In an alpha helix, hydrogen bonds form between amino acids four residues apart.
• Beta sheets in proteins can be parallel or antiparallel
• Why is hydrogen bonding crucial for maintaining secondary structure stability?

  It stabilizes folding patterns
• What type of bonds link amino acids in proteins?

  Peptide bonds
• Amino acids are the monomers of proteins.
• Match the amino acid component with its function:

  Amino group ↔️ Basic group, accepts proton

  Carboxyl group ↔️ Acidic group, donates proton

  R group ↔️ Determines properties
• Steps in forming a peptide bond

  1️⃣ Carboxyl group of one amino acid reacts with amino group of another

  2️⃣ Condensation reaction occurs

  3️⃣ Water molecule is released

  4️⃣ Peptide bond is formed
• The peptide bond has a partial double bond character
• The primary structure of a protein refers to the sequence of amino acids.
• What does the primary structure of a protein determine?

  Higher-level structures