enzymes

• enzymes are biological catalysts, they lower activation energy by reducing the need for energy
• enzymes:

  have a specific tertiary structure to fit substrates

  are reusable in multiple reactions

  are either intracelluclar or extracellular
• induced fit is where hydrogen bonds alter the shape of an active site to better fit substrates
• enzyme activity increases with increased temp, molecules have more energy, so collide more. so more enzyme substrate complexes form. however if temp becomes too high the hydrogen and ionic bonds break, so the active site denatures
• enzymes are affected by ph. a change in ph alters the amino acids that make the active site, so enzyme substrate complexes cant form. there is an optimum ph where ezymes work best, so a greater ph than that would denature it
• as concentration of enzymes increases so does the rate of reaction, this is because the nore enzymes available the more substrate collisions occur making enzymes substrate complexes. if substrate numbers are limited there will be excess enzymes so concentration will have no affect on rate of reaction
• as substrate concentration increases so does rate of reaction. more substrates means a higher chance of collisions. this means there will be more occupied active sites. however a saturation point will be reached where there are more substrates than enzymes so maximum amount of enzyme substrate complexes is reached
• competeive inhibititors have similar structures to substrates, but when bonded to the active site no reaction takes place, the blocked active sites reduce enzyme substrate complexes
• non-competive inhibitors are molecules that bind to en enzyme away from an active site, this causes a change in the shape of the active site, meaning enzyme substrate complexes cant be formed.
• the properties of enzymes are related to their tertiary structure that determines the shape of their active site.
• enzymes are specific to one molecule so only catalyse one reaction.
• a change in tertiary srtructure would alter the shape of the active site. the change in tertiary structure would be caused by a change in the primary structure of amino acids. if a mutation occurs in the gene that codes for the sequence of amino acids, it would change the tertiary structure