2.3.2 - Factors affecting enzyme activity

HideShow resource information


  • Enzyme controlled reactions increase when temperature increases. More heat means more kinetic energy, so the molecules move around faster. This makes the enzymes more likely to collide with substrate molecules. The energy of these collisions is also increased, which means that each collision is more likely to result in a reaction. But if the temperature gets too high, the reaction will stop altogether, because the vibration breaks some of the bonds that hold the enzyme in shape. The active site changes shape and the enzyme and substrate no longer fits together. At this point, the enzyme is denatured (no longer functions as a catalyst) 


  • All enzymes have an optimum pH level. Most human enzymes work best at pH7 (neutral), but there are exceptions. Pepsin for example, works best at pH2,


No comments have yet been made

Similar Biology resources:

See all Biology resources »See all Biological molecules, organic chemistry and biochemistry resources »