Proteins: Structure and Functions Quiz

Proteins: Structure, Function, and Composition

• Proteins are essential biomolecules found in all living organisms. They play a crucial role in various bodily processes, including digestion, cell activity, and oxygen transport.
• Proteins are composed of amino acids linked by peptide bonds, forming polypeptide chains. Approximately 20 different amino acids make up proteins.
• Protein structure is determined by the sequence of amino acids and subsequent folding, facilitated by hydrogen bonds.

Protein Functions

• Proteins perform six major functions:
  • Providing structure: Collagen and keratin are examples of structural proteins crucial for supporting tissues like bones, skin, and hair.
  • Regulating body processes: Enzymes, like those involved in digestion, accelerate chemical reactions. Protein hormones, such as insulin, regulate cellular functions.
  • Transporting materials: Hemoglobin transports oxygen from the lungs to body tissues.
  • Balancing fluids: Albumin and globulin help regulate fluid balance in the blood.
  • Helping with immunity: Antibodies, PRRs (pattern recognition receptors), complement proteins, and interferons contribute to the immune response.
  • Providing energy: Proteins are a source of energy when carbohydrates and fats are insufficient.

Protein Composition and Structure

• Proteins are chains of amino acids.
• Amino acids have an amino group and a carboxyl group. The differing 'R' group is what distinguishes amino acids.
• Protein structure is determined by the specific arrangement of amino acids and the resulting three-dimensional shape.

Detailed Protein Functions

• Providing Structure (Structural Proteins):
  • Collagen is abundant in bones, connective tissues, and skin, providing strength.
  • Keratin is found in hair, nails, skin, and organ linings, providing protection and structure.
• Regulating Body Processes (Enzymes & Hormones):
  • Enzymes such as those in digestion accelerate reactions for optimal bodily function.
  • Hormones like insulin affect metabolic processes and cell function.
• Transporting Materials (Transport Proteins):
  • Hemoglobin facilitates oxygen transport in red blood cells.
  • Other transport proteins move ions or molecules across membranes.
• Balancing Fluids (Fluid Balance Proteins):
  • Albumin and globulin maintain fluid balance by attracting and retaining water in the blood. This is vital for metabolic function, as insufficient fluid balance can lead to problems in organs like the heart and kidneys.
• Helping with Immunity (Immune System Proteins): - PRRs (pattern recognition receptors) detect foreign invaders. - Antibodies target and neutralize foreign antigens. - Complement proteins and interferons support the immune response against infection.
• Providing Energy (Protein Breakdown):
  • When insufficient carbohydrates or fats are available, proteins can be broken down for energy.
  • This breakdown results in nitrogen waste (urea), which must be eliminated by the kidneys.