What is an enzyme and what effect does temperature have on enzyme activity? (6 marks)

  • Google+ icon
  • LinkedIn icon
  • 761 views

An enzyme is a globular protein that acts as a biological catalyst.  They work by reducing the activation energy of chemical reactions, which increases the rate of reactions.

All enzymes have an optimum temperature.  

The rate of reaction increases as temperature increases, up to the optimum temperature.  This is because both the enzyme and substrate molecules have more kinetic energy so move around faster and are more likely to collide.  A collision creates an enzyme substrate complex, which triggers the catalytic effect.  

As temperature rises above the optimum temperature the particles with the molecule vibrate more energetically, which cause the bonds to break.  This means that the active site changes shape and the enzyme becomes denatured.  Enzyme substrate complexes can no longer form and the catalytic effect is lost.   

Isabel O. A Level Biology tutor, A Level Chemistry tutor, A Level Che...

About the author

is an online A Level Biology tutor with MyTutor studying at Exeter University

Still stuck? Get one-to-one help from a personally interviewed subject specialist.

95% of our customers rate us

Browse tutors

We use cookies to improve your site experience. By continuing to use this website, we'll assume that you're OK with this. Dismiss

mtw:mercury1:status:ok