factors affecting enzymes activity

• enzymes are biological catalysts that speed up chemical reactions
• the active site is the part of an enzyme where substrate molecules bind to form an enzyme-substrate complex.
• the product(s) of the reaction then dissociates from the enzyme, leaving it free to react again with another molecule of substrate.
• increasing temperature increases kinetic energy of particles so they collide successfully more frequently, increasing rate of reaction
• what is the temperature coefficient of a reaction?

  measure of how much the rate of reaction increases with 10 degrees temperature increase
• what are the four main factors affecting rate of enzyme-controlled reactions?

  pH, temperature, enzyme concentration, substrate concentration
• why does rate of reaction decrease once enzymes are denatured?

  active site changes shape, substrate no longer fits
• what is Q10?


  temperature coefficient
• at higher temperature the bonds holding the protein together vibrate more until they break. this results in a change in the tertiary structure of the protein. the enzyme has denatured
• when an enzyme is denatured the active site changes shape and is no longer complementary to the substrate
• when does the temperature coefficient stop applying?

  denaturation
• when concentration of substrate / enzymes increases, there are more frequent collisions with the active site and substrate.
• why does rate of reaction plateau with conc. of substrate/enzyme?

  all active sites are occupied by the substrates