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
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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
Biology
30 Nov 2025
165
3 pages
Haida Zeb @haidazeb_
Enzymes are the biochemical superstars that make life possible - without them, the hundreds of reactions happening in... Show more
Think of enzymes as molecular machines that keep every cell in your body running smoothly. These large globular proteins are responsible for catalysing nearly every biochemical reaction you need to survive, from breaking down your lunch to copying your DNA.
What makes enzymes so special is their structure. Although they're massive molecules, only a tiny part called the active site does the actual work - sometimes just a few amino acids! The rest of the protein acts like scaffolding, maintaining the enzyme's precise shape.
Substrate specificity is what makes each enzyme unique. Some are incredibly picky - catalase only breaks down hydrogen peroxide (that toxic stuff your cells accidentally make). Others are more flexible, like lipases that can break down various fats into fatty acids and glycerol.
Quick Tip Remember that enzymes work both inside cells (intracellularly) and outside them (extracellularly) - like pepsin digesting your food in your stomach!
Many enzymes are like talented musicians who need the right instrument to perform - they require cofactors to function properly. These non-protein helpers come in two main varieties, each with their own role.
Activators are inorganic ions like iron, zinc, and copper that permanently attach to enzymes. Think of them as built-in tools that never leave the enzyme's toolkit. Without these metal cofactors, many enzymes would be completely useless.
Coenzymes are the temporary helpers - organic molecules that pop in and out of reactions, often carrying chemical groups from one reaction to another. Vitamin C and ATP are classic examples that your body constantly recycles.
Understanding cofactors explains why vitamin deficiencies can be so serious - without these essential coenzymes, entire metabolic pathways can grind to a halt, affecting your health dramatically.
Real-World Connection This is why a balanced diet matters so much - you're not just feeding yourself, you're supplying the cofactors your thousands of enzymes need to keep you alive!
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.
6
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Explore 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 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 key factors affecting enzyme activity, including temperature, pH, enzyme concentration, and substrate concentration. This summary covers the mechanisms of enzyme action, the induced-fit model, competitive inhibition, and practical investigations into enzyme kinetics. Ideal for A Level Biology students preparing for exams.
BiologyExplore the role of enzymes as biological catalysts, including the enzyme-substrate complex, induced fit model, and types of inhibition (competitive and non-competitive). This summary covers key concepts such as enzyme concentration, reaction rates, and the impact of pH on enzyme activity, tailored for AQA specifications.
BiologyExplore essential methods for crop protection in higher biology, including pest control techniques, the impact of weeds, plant diseases, and the principles of integrated pest management. This summary covers key concepts such as bioaccumulation, biomagnification, and the use of pesticides, providing a comprehensive overview for students studying plant health and productivity.
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
Haida Zeb
@haidazeb_
Enzymes are the biochemical superstars that make life possible - without them, the hundreds of reactions happening in your cells every second would be far too slow to sustain life. These incredible protein catalysts can speed up reactions by millions... Show more
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Think of enzymes as molecular machines that keep every cell in your body running smoothly. These large globular proteins are responsible for catalysing nearly every biochemical reaction you need to survive, from breaking down your lunch to copying your DNA.
What makes enzymes so special is their structure. Although they're massive molecules, only a tiny part called the active site does the actual work - sometimes just a few amino acids! The rest of the protein acts like scaffolding, maintaining the enzyme's precise shape.
Substrate specificity is what makes each enzyme unique. Some are incredibly picky - catalase only breaks down hydrogen peroxide (that toxic stuff your cells accidentally make). Others are more flexible, like lipases that can break down various fats into fatty acids and glycerol.
Quick Tip: Remember that enzymes work both inside cells (intracellularly) and outside them (extracellularly) - like pepsin digesting your food in your stomach!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Many enzymes are like talented musicians who need the right instrument to perform - they require cofactors to function properly. These non-protein helpers come in two main varieties, each with their own role.
Activators are inorganic ions like iron, zinc, and copper that permanently attach to enzymes. Think of them as built-in tools that never leave the enzyme's toolkit. Without these metal cofactors, many enzymes would be completely useless.
Coenzymes are the temporary helpers - organic molecules that pop in and out of reactions, often carrying chemical groups from one reaction to another. Vitamin C and ATP are classic examples that your body constantly recycles.
Understanding cofactors explains why vitamin deficiencies can be so serious - without these essential coenzymes, entire metabolic pathways can grind to a halt, affecting your health dramatically.
Real-World Connection: This is why a balanced diet matters so much - you're not just feeding yourself, you're supplying the cofactors your thousands of enzymes need to keep you alive!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
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.
6
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Explore 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 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 key factors affecting enzyme activity, including temperature, pH, enzyme concentration, and substrate concentration. This summary covers the mechanisms of enzyme action, the induced-fit model, competitive inhibition, and practical investigations into enzyme kinetics. Ideal for A Level Biology students preparing for exams.
BiologyExplore the role of enzymes as biological catalysts, including the enzyme-substrate complex, induced fit model, and types of inhibition (competitive and non-competitive). This summary covers key concepts such as enzyme concentration, reaction rates, and the impact of pH on enzyme activity, tailored for AQA specifications.
BiologyExplore essential methods for crop protection in higher biology, including pest control techniques, the impact of weeds, plant diseases, and the principles of integrated pest management. This summary covers key concepts such as bioaccumulation, biomagnification, and the use of pesticides, providing a comprehensive overview for students studying plant health and productivity.
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
