Enzymes as Biological Catalysts in Chemical Reactions

Enzymes as Biological Catalysts in Chemical Reactions

Introduction to Enzymes

  • Enzymes are biological catalysts that speed up chemical reactions in cells without being consumed in the reaction itself.
  • Made up of proteins, enzymes have complex structures that enable them to bind with substrates and carry out specific reactions.
  • The region of an enzyme where substrate molecules bind and undergo a chemical reaction is called the active site.

Enzyme-Substrate Interaction

  • Enzymes work based on the lock and key model, where the enzyme (the lock) has a shape that perfectly fits the substrate (the key).
  • This unique fit creates an enzyme-substrate complex, which facilitates the reaction.
  • After the reaction, the enzyme releases the product and is free to bind with new substrate molecules.

Roles of Enzymes in Metabolic Reactions

  • Enzymes play a critical role in metabolic reactions, acting as catalysts to convert substrates into products.
  • They are essential for various biological processes such as digestion, respiration, DNA replication, and protein synthesis.
  • Each enzyme is specific to a certain reaction, determined by its structure and the shape of its active site.

Factors Affecting Enzyme Activity

  • The rate of enzyme-catalysed reactions can be affected by factors such as temperature, pH, enzyme concentration, and substrate concentration.
  • Each enzyme has its optimum temperature and pH at which it works most efficiently.
  • High temperature or extreme pH can cause denaturation of enzymes, where the protein structure unravels and the enzyme loses its function.

Enzyme Inhibition

  • Enzyme inhibitors are molecules that bind to enzymes and decrease their activity. They can be competitive (competing with the substrate for the active site) or non-competitive (binding elsewhere and changing the enzyme’s shape).

Remember: Enzymes are biological catalysts that work based on the lock and key model, and their activity can be affected by various environmental factors. Incorrect conditions can lead to denaturation, rendering the enzyme inactive.