substrate conc

• the higher the substrate concentration the faster the rate of reaction - more substrate molecules means a collision between substrate and enzyme is more likely so more active sites will be used
• there becomes a point where there are more substrate molecules than the enzymes can cope with so adding more substrate has no effect on the reaction
• substrate concentration decreases with time during a reaction so if no other variables are changed, the rate of reaction will decrease making the initial rate of the reaction the highest rate