The enzymes which catalyze the same reaction but have different amino acid compositions are commonly referred as :

The correct answer is Isoenzymes.

Key Points

• Isoenzymes are enzymes that catalyze the same chemical reaction but differ in their amino acid sequences and structure.
• They are encoded by different genes and may vary in their kinetic properties, regulatory mechanisms, or tissue-specific expression.
• Isoenzymes often play a key role in adapting enzyme activity to specific tissues or developmental stages.
• A classic example of isoenzymes is lactate dehydrogenase (LDH), which has multiple forms adapted for different tissues such as the heart and skeletal muscles.
• These enzymes provide functional diversity and help in maintaining metabolic control under varying physiological conditions.

Additional Information

• Coenzymes:
  • Coenzymes are organic molecules that bind to enzymes and assist in catalyzing reactions.
  • Examples include NAD+ (Nicotinamide Adenine Dinucleotide) and FAD (Flavin Adenine Dinucleotide).
  • They act as carriers for chemical groups or electrons during enzymatic reactions.
• Isomers:
  • Isomers are molecules with the same molecular formula but different structural arrangements.
  • They are not related to enzymatic activity but are important in organic chemistry.
• Isotopes:
  • Isotopes are atoms of the same element that have different numbers of neutrons, leading to varying atomic masses.
  • They are used in radiological studies and not associated with enzyme function.
• Lactate Dehydrogenase (LDH) Isoenzymes:
  • LDH has five isoenzymes (LDH-1 to LDH-5) that are tissue-specific.
  • LDH-1 is primarily found in the heart, while LDH-5 is predominant in the liver and muscles.