enzymes

How do enzyme properties relate to their tertiary structure

• enzymes are highly specific due to their tertiary structure

• The active sites shape is determined by the enzymes tertiary structure

• The tertiary structure of an enzyme may be altered by changes in the pH or temperature

• The primary structure of a protein is determined by a gene. If a mutation occurs in that gene it could change the tertiary structure of the enzyme produced

How do enzymes change activation energy

• enzymes lower the amount of activation energy that needed, making reactions happen at a lower temperature which speeds up rate of reaction

• The enzyme substrate complex lower the activation energy (an enzyme substrate complex is formed when a substrate fits into the enzymes active site)

Whats induced fit

• the active site changes shape slightly to be complementary to the substrate

• Induced fit model explains why enzymes are so specific

Factors affecting enzyme activity

Temperature - if too low theres not enough kinetic energy for successful collisions between enzyme and substrate and if too high enzymes denature, active site changes shape and enzyme - substrate complex cannot form

pH - too high or too low can interfere with the charges in the amino acids in the active site. This can break bonds holding tertiary structure and active site changes shape, therefore enzymes denature and fewer enzyme - substrate complexes form

Substrate and enzyme concentration - if theres insufficient substrate, reaction will be slower as theres fewer collisions between enzyme and substrate, if theres insufficient enzymes, enzyme active sites will become saturated with substrate and unable to work any faster

Enzyme inhibitors - (competitive) are the same shape as substrate and can bind to active site, this prevents substrate from binding and reaction occurring (non-competitive) bind to enzyme away from active site and this causes active site to change shape so substrate can no longer bind