1.4 Proteins

• Proteins serve as structural components, enzymes, antibodies, and signaling molecules
• Match the groups attached to the central carbon atom in an amino acid with their descriptions:

  Carboxyl group ↔️ -COOH

  Amino group ↔️ -NH2

  Hydrogen atom ↔️ -H

  R-group ↔️ Side chain
• What is the primary structure of a protein determined by?

  Sequence of amino acids
• Understanding protein structure is essential for comprehending protein function.


  True
• What does the amino group in an amino acid contribute to?

  Peptide bonds
• What are the reactants in peptide bond formation?

  Carboxyl group and amino group
• What determines the tertiary structure of a protein?

  Interactions within the chain
• Match the protein function with its description:

  Structural ↔️ Provides support and shape to cells

  Enzymatic ↔️ Catalyzes biochemical reactions

  Hormonal ↔️ Regulates body functions

  Immunological ↔️ Defends against pathogens
• Protein denaturation refers to the disruption of the native three-dimensional structure
• When a protein is denatured, it loses its native 3D structure
• Arrange the groups bonded to the central carbon of an amino acid:

  1️⃣ Carboxyl group (-COOH)

  2️⃣ Amino group (-NH2)

  3️⃣ Hydrogen atom (-H)

  4️⃣ R-group (side chain)
• Common secondary structures include alpha helices and beta sheets
• Understanding protein structure is crucial for understanding protein function.


  True
• The tertiary structure of a protein is its overall three-dimensional shape.

  True
• How does high temperature affect protein conformation?

  Breaks hydrogen bonds and hydrophobic interactions
• Enzymes are a special class of proteins that function as catalysts
• What is the primary bond that links amino acids in proteins?

  Peptide bond
• What is the central atom in an amino acid structure?

  Carbon atom
• Steps involved in the formation of a peptide bond

  1️⃣ The carboxyl group (-COOH) of one amino acid reacts with the amino group (-NH2) of another.

  2️⃣ A water molecule (H2O) is released in a condensation reaction.

  3️⃣ A covalent peptide bond is formed.
• Match the level of protein structure with its description:

  Primary ↔️ Sequence of amino acids

  Secondary ↔️ Local folding patterns

  Tertiary ↔️ Overall 3D shape

  Quaternary ↔️ Arrangement of multiple chains
• The carboxyl group in an amino acid has the formula -COOH
• Describe the process of peptide bond formation in a condensation reaction.

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

  2️⃣ A water molecule (H2O) is released.

  3️⃣ A peptide bond forms, linking the amino acids together.

  4️⃣ Polypeptides are formed, which are the primary structures of proteins.
• Secondary structures in proteins, such as alpha helices and beta sheets, are stabilized by hydrogen bonds.

  True
• Which factors can affect protein conformation?

  Temperature, pH, ionic strength
• High temperatures can denature proteins by breaking hydrogen bonds and hydrophobic interactions.


  True
• High ionic strength can affect protein folding by disrupting electrostatic interactions


  True
• Proteins are composed of amino acids linked by peptide bonds
• Match the level of protein structure with its description:

  Primary ↔️ Sequence of amino acids

  Secondary ↔️ Local folding patterns

  Tertiary ↔️ Overall 3D shape

  Quaternary ↔️ Arrangement of multiple subunits
• What is the quaternary structure of a protein?

  Arrangement of multiple polypeptide chains
• What are the common secondary structures in proteins?

  Alpha helices and beta sheets
• Protein denaturation refers to the disruption of a protein's native three-dimensional structure
• What does high ionic strength do to protein conformation?

  Interferes with electrostatic interactions
• Order the steps involved in protein denaturation due to high temperature:

  1️⃣ High temperature occurs

  2️⃣ Hydrogen bonds and hydrophobic interactions break

  3️⃣ Protein unfolds

  4️⃣ Loss of enzymatic activity
• Proteins are indispensable for the proper functioning of living organisms.


  True
• The R-group determines the unique properties of each amino acid.


  True
• Alpha helices and beta sheets are examples of protein secondary structures.
• What is the central atom in an amino acid structure?

  Carbon
• The R-group in an amino acid is the only feature that distinguishes different amino acids.


  True
• The primary structure of a protein is the sequence of amino acids.
• The quaternary structure of a protein involves the arrangement of multiple polypeptide chains.