Why are enzymes called biological catalysts?

Short Answer

Enzymes are called biological catalysts because they speed up chemical reactions in living organisms without being used up. They help important life processes such as digestion, respiration, and metabolism occur quickly at normal body conditions. Without enzymes, these reactions would be too slow to support life.

Enzymes are biological because they are produced by living cells and are mostly proteins. They act as catalysts by lowering the energy required to start chemical reactions, making life processes efficient and continuous.

Detailed Explanation :

Enzymes as Biological Catalysts

Enzymes are essential biomolecules that control all chemical reactions in living organisms. The term biological catalyst is used for enzymes because they perform the same role as chemical catalysts but within living systems. They increase the speed of reactions without being consumed or permanently changed. This unique property makes enzymes vital for survival.

Meaning of biological catalyst

  • Catalyst
    • A catalyst is a substance that speeds up a chemical reaction.
    • It does not get used up during the reaction.
    • It remains unchanged after the reaction is complete.
  • Biological
    • Biological means related to living organisms.
    • Enzymes are produced inside living cells.
    • They function only in biological systems.
  • Biological catalyst
    • Enzymes are called biological catalysts because:
      • They speed up reactions.
      • They work inside living cells.
      • They are not consumed in the reaction.

How enzymes speed up reactions

  • Lowering activation energy
    • Every chemical reaction needs energy to start.
    • This starting energy is called activation energy.
    • Enzymes lower this activation energy.
  • Formation of enzyme–substrate complex
    • Enzyme binds with its specific substrate.
    • A temporary enzyme–substrate complex is formed.
    • This complex makes the reaction easier and faster.
  • Release of products
    • After the reaction, products are released.
    • The enzyme remains free to work again.

Specific nature of enzymes

  • High specificity
    • Each enzyme works on a specific substrate.
    • This prevents unnecessary reactions.
    • It ensures accuracy in metabolic processes.
  • Lock and key concept
    • The enzyme and substrate fit together.
    • This fit allows the reaction to occur easily.
  • Biological control
    • Specificity helps cells control reactions.
    • Only required reactions take place.

Enzymes are not used up

  • Reusable nature
    • Enzymes are not consumed during reactions.
    • One enzyme molecule can catalyze many reactions.
  • Efficiency
    • A small amount of enzyme can act on large amounts of substrate.
    • This makes enzymes highly efficient.
  • Stability
    • Under proper conditions, enzymes remain stable.
    • They continue functioning for a long time.

Enzymes work under mild conditions

  • Normal temperature
    • Enzymes work at normal body temperature.
    • Chemical catalysts often need high temperature.
  • Normal pH
    • Enzymes work best at specific pH values.
    • They function in mild conditions suitable for life.
  • Safety for cells
    • Mild conditions prevent damage to cells.
    • Enzymes make life possible under gentle conditions.

Importance of enzymes in metabolism

  • Control of metabolic reactions
    • All metabolic reactions are enzyme-controlled.
    • Without enzymes, metabolism cannot occur.
  • Fast reaction rate
    • Enzymes speed up reactions millions of times.
    • This supports continuous life processes.
  • Coordination
    • Enzymes coordinate different metabolic pathways.
    • They maintain balance in the body.

Difference between enzymes and chemical catalysts

  • Source
    • Enzymes are produced by living cells.
    • Chemical catalysts are made artificially.
  • Specificity
    • Enzymes are highly specific.
    • Chemical catalysts are less specific.
  • Conditions
    • Enzymes work under mild conditions.
    • Chemical catalysts often need extreme conditions.
  • Efficiency
    • Enzymes are more efficient.
    • Chemical catalysts are slower in comparison.

Examples showing catalytic role of enzymes

  • Digestion
    • Digestive enzymes break food into simple substances.
    • This happens quickly due to enzymes.
  • Respiration
    • Enzymes help release energy from glucose.
    • Energy is produced efficiently.
  • Photosynthesis
    • Plant enzymes help make food.
    • Reactions occur at normal temperatures.

Importance for survival

  • Life processes
    • Life processes depend on enzymes.
    • Without enzymes, life stops.
  • Energy efficiency
    • Enzymes save energy.
    • They prevent waste of cellular energy.
  • Adaptation
    • Enzymes allow quick response to changes.
    • They help organisms adapt.
Conclusion

Enzymes are called biological catalysts because they speed up chemical reactions in living organisms without being used up. They are produced by living cells and work efficiently under normal biological conditions. By lowering activation energy and controlling specific reactions, enzymes make life processes fast, safe, and efficient. Without enzymes, metabolic reactions would be too slow, and life would not be possible.