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

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.   

IO
Answered by Isabel O. Biology tutor

15523 Views

See similar Biology A Level tutors

Related Biology A Level answers

All answers ▸

It has been suggested that smoking, an epigenetic factor can lead to tumour growth and cancer. Use your knowledge of the epigenome and its structure to explain how this could occur. [5 marks]


What are the advantages of saltatory conduction?


What factors affect the rate of conduction of an action potential (AP) down a neurone?


What's the difference between genetic code, genetic material and genetic information?


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2025 by IXL Learning