1.6 Enzymes

1.6 Enzymes

Biological Catalysts

• Speed up chemical reactions, such as metabolic reactions, at a cellular level (respiration) and for an organism as a whole (digestion).
• Can affect the structures in an organism (Collagen).
• Enzyme action can be extracellular (outside cells) or intracellular (within cells)
• Enzymes are proteins.
• Have active site with a specific shape determined by it's tertiary structure.
• Active site is part of the enzyme where the substrate binds to form an enzyme-substrate complex.

How Enzymes speed up reactions

• Activation Energy = Minimum energy required to start a reaction - energy often supplied as heat.
• Enzymes lower activation energy, so reactions can happen at a lower temperature, so rate of reaction is faster.
• Enzyme substrate complex lowers the activation enrgy by:
• 1. If molecules need to be joined, the enzyme holds substrates together…