Chapter 4: Enzymes

Enzymes

Are ^^biological catalysts^^ made of ^^proteins^^. They ^^alter the rate of chemical reactions^^ without being chemically changed at the end of reaction and are specific nature.

Enzyme-Catalysed Reaction:

  • %%Amylase%% digests starch.
  • %%Cellulase%% digests cellulose (only in plants not in humans).
  • %%Protease%% digests proteins.
  • %%Lipase%% digests fats.

Characteristics of Enzymes:

  • Speed up chemical reactions.
  • Required in minute amounts.
  • Are specific.

Factors affecting Enzyme Activity:

  • %%pH%%: they work ^^best at optimum pH^^. As pH ^^moves away from the pH scale the rate of reaction decreases^^. A ^^change in pH causes the shape of active site to change.^^
  • %%Temperature%%: works ^^best at optimum temperature^^. At a temperature ^^above optimum temperature the enzyme denatures.^^
  • %%Enzyme and Substrate concentration%%: as the ^^substrate concentration increases the rate of reaction increases to an initial point to make reaction constant^^ + Increase in enzyme concentration increases rate of enzyme reaction.

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Lock and Key hypothesis:

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