Condensation Reaction

Condensation Reaction in Proteins

• A condensation reaction specific to proteins involves the joining of amino acids.
• In this process, the hydroxyl group (OH) leaves, and the carbonyl group of one amino acid binds to the amine group of another.
• This connection forms a peptide bond, which is the bond that holds amino acids together in a protein.

Peptide Bonds

• Peptide bonds are crucial for linking amino acids within a protein.
• Amino acids continue to be added until the entire protein is formed.

Polypeptides

• Proteins are synthesized in ribosomes.
• Initially, a protein is created in a linear form known as a polypeptide.
• A polypeptide doesn't have its functional capabilities until it folds into a specific shape.
• Once properly folded, the polypeptide becomes a functional protein.

Types of Proteins

• There are two main types of proteins:
  • Monomeric: Contains only one polypeptide chain.
  • Multimeric: Contains more than one polypeptide chain.

Hemoglobin as a Multimeric Protein

• Hemoglobin serves as an example of a multimeric protein.
• It consists of two beta-globin polypeptides and two alpha-globin polypeptides.
• In total, hemoglobin is composed of four different polypeptide chains.
• These chains assemble and fold correctly to create the functional hemoglobin protein.
• If globin exists alone, it would be considered a monomeric protein because it is a single polypeptide.
• However, when globin combines with other polypeptides to form the complete hemoglobin protein, it becomes a multimeric protein.