Subjects
Maths
Biology
Chemistry
English Language
History
Responding to change (a2 only)
Infection and response
Homeostasis and response
Energy transfers (a2 only)
Cell biology
Organisms respond to changes in their internal and external environments (a-level only)
Biological molecules
Organisation
Substance exchange
Bioenergetics
Genetic information & variation
Inheritance, variation and evolution
Genetics & ecosystems (a2 only)
Ecology
Cells
Show all topics
1l the quest for political stability: germany, 1871-1991
Britain & the wider world: 1745 -1901
The cold war
Inter-war germany
Medieval period: 1066 -1509
2d religious conflict and the church in england, c1529-c1570
2o democracy and nazism: germany, 1918-1945
1f industrialisation and the people: britain, c1783-1885
1c the tudors: england, 1485-1603
2m wars and welfare: britain in transition, 1906-1957
World war two & the holocaust
2n revolution and dictatorship: russia, 1917-1953
2s the making of modern britain, 1951-2007
World war one
Britain: 1509 -1745
Show all topics
108
•
4 Dec 2025
•
Olivia
@oliviag
Understanding what affects enzyme activity is crucial for your biology... Show more
Ever wondered why you get a fever when you're ill? Your body's enzymes work best at specific temperatures, and understanding this relationship is essential for your exams.
Temperature increases boost enzyme activity initially because molecules gain kinetic energy and move faster, leading to more frequent collisions between enzymes and substrates. Most human enzymes hit their optimum temperature around 40°C - any hotter and you'd be in serious trouble!
Beyond the optimum temperature, enzymes become denatured. Their protein structure breaks down, changing the shape of the active site so it no longer fits the substrate. Think of it like a lock getting bent - the key simply won't work anymore.
Quick Tip: The temperature coefficient (Q10) measures how much reaction rates increase with every 10°C rise - a handy concept for exam calculations!
Some organisms have adapted brilliantly to extreme temperatures. Thermophiles living in hot springs have enzymes with extra bonds for stability, whilst organisms in polar regions have more flexible enzyme structures to function in the cold.
Your stomach acid could dissolve metal, yet your saliva is nearly neutral - this dramatic pH difference shows how enzymes are perfectly adapted to their specific environments.
Each enzyme has an optimum pH where it works most effectively. Stray too far from this sweet spot and the enzyme becomes denatured as acid or alkaline conditions break the bonds holding its structure together. Unlike temperature denaturation, mild pH changes can sometimes be reversed if conditions return to normal quickly.
Your digestive system showcases this beautifully. Pepsin thrives in your stomach's acidic environment , breaking down proteins. Meanwhile, pancreatic enzymes like trypsin and lipase work in the slightly alkaline conditions of your small intestine (pH 8).
Exam Alert: Learn the specific pH ranges and enzyme locations - they're exam favourites!
This pH specialisation ensures each enzyme works optimally exactly where it's needed, from amylase starting starch digestion in your mouth to maltase finishing the job in your intestines.
Picture a busy restaurant kitchen - more ingredients means faster cooking, but only until you run out of chefs. Substrate concentration works similarly with enzymes.
Initially, increasing substrate concentration boosts reaction rates because there are more substrate molecules available to bind with enzyme active sites. More enzyme-substrate complexes form, speeding up the overall reaction significantly.
However, this doesn't continue forever. Eventually you reach Vmax - the maximum reaction rate where all active sites are occupied. At this point, adding more substrate won't increase the rate because enzyme concentration becomes the limiting factor.
Key Concept: At Vmax, all enzymes are working flat out - they're saturated with substrate!
To push beyond Vmax, you'd need to add more enzymes (not just substrates) to provide additional active sites. This principle explains why your body produces different amounts of enzymes depending on your needs - more food means more digestive enzymes required!
Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.
You can download the app from Google Play Store and Apple App Store.
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
App Store
Google Play
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
Olivia
@oliviag
Understanding what affects enzyme activity is crucial for your biology A-levels and explains how your body's chemical reactions work efficiently. Temperature, pH, and substrate concentration all play vital roles in determining how fast enzymes can catalyse reactions.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Ever wondered why you get a fever when you're ill? Your body's enzymes work best at specific temperatures, and understanding this relationship is essential for your exams.
Temperature increases boost enzyme activity initially because molecules gain kinetic energy and move faster, leading to more frequent collisions between enzymes and substrates. Most human enzymes hit their optimum temperature around 40°C - any hotter and you'd be in serious trouble!
Beyond the optimum temperature, enzymes become denatured. Their protein structure breaks down, changing the shape of the active site so it no longer fits the substrate. Think of it like a lock getting bent - the key simply won't work anymore.
Quick Tip: The temperature coefficient (Q10) measures how much reaction rates increase with every 10°C rise - a handy concept for exam calculations!
Some organisms have adapted brilliantly to extreme temperatures. Thermophiles living in hot springs have enzymes with extra bonds for stability, whilst organisms in polar regions have more flexible enzyme structures to function in the cold.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Your stomach acid could dissolve metal, yet your saliva is nearly neutral - this dramatic pH difference shows how enzymes are perfectly adapted to their specific environments.
Each enzyme has an optimum pH where it works most effectively. Stray too far from this sweet spot and the enzyme becomes denatured as acid or alkaline conditions break the bonds holding its structure together. Unlike temperature denaturation, mild pH changes can sometimes be reversed if conditions return to normal quickly.
Your digestive system showcases this beautifully. Pepsin thrives in your stomach's acidic environment , breaking down proteins. Meanwhile, pancreatic enzymes like trypsin and lipase work in the slightly alkaline conditions of your small intestine (pH 8).
Exam Alert: Learn the specific pH ranges and enzyme locations - they're exam favourites!
This pH specialisation ensures each enzyme works optimally exactly where it's needed, from amylase starting starch digestion in your mouth to maltase finishing the job in your intestines.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Picture a busy restaurant kitchen - more ingredients means faster cooking, but only until you run out of chefs. Substrate concentration works similarly with enzymes.
Initially, increasing substrate concentration boosts reaction rates because there are more substrate molecules available to bind with enzyme active sites. More enzyme-substrate complexes form, speeding up the overall reaction significantly.
However, this doesn't continue forever. Eventually you reach Vmax - the maximum reaction rate where all active sites are occupied. At this point, adding more substrate won't increase the rate because enzyme concentration becomes the limiting factor.
Key Concept: At Vmax, all enzymes are working flat out - they're saturated with substrate!
To push beyond Vmax, you'd need to add more enzymes (not just substrates) to provide additional active sites. This principle explains why your body produces different amounts of enzymes depending on your needs - more food means more digestive enzymes required!
Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.
You can download the app from Google Play Store and Apple App Store.
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
4
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Explore the essential role of enzymes in biochemical reactions, including their structure, function, and mechanisms of action. This summary covers key concepts such as the active site, enzyme specificity, types of inhibitors, and factors affecting enzyme activity. Ideal for A-Level students seeking a comprehensive overview of enzymatic processes.
BiologyExplore the essential roles of enzymes in biological reactions with this detailed overview. Understand the enzyme-substrate complex, the significance of active sites, and the impact of temperature and pH on enzyme activity. Ideal for biology students seeking to grasp the fundamentals of enzymatic processes.
BiologyExplore the mechanisms of enzyme inhibitors, focusing on competitive and non-competitive inhibition. This summary covers key concepts such as the active site, allosteric site, and the enzyme-substrate complex, providing insights into how inhibitors affect reaction rates. Ideal for students studying biological molecules.
BiologyExplore the key concepts of enzyme activity, including examples like catalase, amylase, and trypsin. Understand how temperature, pH, enzyme concentration, and substrate concentration affect reaction rates. This summary covers the Lock & Key and Induced Fit models, emphasizing the role of enzymes as biological catalysts that lower activation energy. Ideal for A-Level Biology students across all exam boards.
BiologyExplore the mechanisms of cyanide poisoning and the role of enzymes in biological processes. This study note covers key concepts such as enzyme-substrate interactions, the impact of cyanide on cellular respiration, and the importance of maintaining homeostasis. Ideal for AQA Biology students preparing for exams, this resource includes past paper questions and detailed explanations of enzyme activity and DNA replication.
BiologyExplore the role of enzymes as biological catalysts in digestion, including key digestive enzymes like amylase, proteases, and lipases. Understand how temperature and pH affect enzyme activity and the concept of denaturation. This summary provides essential insights for biology students studying enzyme kinetics and digestion.
BiologyApp Store
Google Play
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
