- the higher the substrate concentration, the faster the reaction
- more substrate means a collision between substrate and enzyme is more likely
more active sites used
- only true up until a 'Saturation Point'
after that, there are so many substrate molecules that the enzymes have about as much as they can cope with (all the active sites are full)
- adding more substrate makes no difference to the rate
- substrate concentration decreases with time during a reaction (unless more substrate is added), so if no other variables are changed, the rate of reaction will decrease over time
- this makes the initial rate of reaction, the highest rate of reaction