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essie
24/09/2025
Biology
GCSE Biology - Enzymes
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24 Sept 2025
•
Learn Enzymes: Lock and Key vs. Induced Fit Models for Kids
essie
@academia_angel
1 / 4
Induced Fit Model and Reaction Rates
Induced Fit Model
The induced fit model of enzyme action is an extension of the lock and key theory. This model proposes that the enzyme's active site is more flexible than initially thought.
Definition: The induced fit model suggests that the enzyme changes its shape slightly to fit the substrate better during the reaction process.
This model provides a more accurate representation of enzyme-substrate interactions, accounting for the dynamic nature of protein structures.
Factors Affecting Enzyme Activity
Temperature
Temperature significantly impacts enzyme activity. Each enzyme has an optimum temperature at which it functions best.
Vocabulary: Optimum temperature is the temperature at which an enzyme functions most efficiently.
Highlight: If the temperature exceeds the optimum, the enzyme's shape starts to change, and it becomes denatured, rendering it inactive.
pH
The pH level also plays a crucial role in enzyme activity. Each enzyme has an optimum pH at which it performs most effectively.
Vocabulary: Optimum pH is the pH level at which the enzyme functions best.
Highlight: If the pH surpasses the optimum level, the enzyme will change shape, slowing down the rate of reaction and potentially becoming denatured.
Calculating Enzyme Reaction Rates
Understanding how to calculate enzyme reaction rates is crucial in biochemistry and molecular biology. This knowledge allows scientists to quantify enzyme activity and compare the efficiency of different enzymes or the same enzyme under various conditions.
Formula for Reaction Rate
The rate of an enzyme-catalyzed reaction can be calculated using the following formula:
Rate of Reaction = Change in Product / Time Taken
Example: If an enzyme-controlled reaction produces 30 cm³ of hydrogen gas in 2 minutes, the rate of reaction would be: 30 cm³ / 120 seconds = 0.25 cm³/s
Units of Measurement
When calculating enzyme reaction rates, it's important to use consistent units:
- Change in product: Typically measured in cubic centimeters (cm³)
- Time taken: Usually measured in seconds (s)
- Rate of reaction: Often expressed as cubic centimeters per second (cm³/s)
Highlight: Proper unit conversion is crucial when calculating enzyme reaction rates to ensure accurate results.
Understanding these concepts and calculations is essential for students studying biology, biochemistry, or related fields. It provides a foundation for more advanced studies in enzyme kinetics and metabolic processes.
Enzymes: Structure and Function
Enzymes are essential biological catalysts that increase reaction rates without being consumed in the process. They are large proteins composed of amino acids and have specific active sites that bind to substrates.
Definition: An enzyme is a biological catalyst that increases the rate of reaction without being changed or used in the process.
Vocabulary:
- Substrate: The substance on which an enzyme reacts.
- Active site: A surface on the enzyme that only allows it to bind with certain substrates.
Lock and Key Theory
The lock and key theory in enzymes explains how enzymes and substrates interact. This model suggests that the active site of an enzyme has a specific shape that perfectly complements the shape of its substrate, much like a key fits into a lock.
Example: The lock and key model process involves:
- The substrate colliding with and attaching to the enzyme's active site.
- The enzyme catalyzing the breakdown of the substrate.
- The products being released from the active site.
Highlight: The enzyme molecule remains unchanged after the reaction and can be reused, making it an efficient catalyst.
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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
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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
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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
Learn Enzymes: Lock and Key vs. Induced Fit Models for Kids
essie
@academia_angel
Enzymes are biological catalysts that speed up chemical reactions in living organisms. They play a crucial role in various metabolic processes. This summary explores the structure and function of enzymes, including the lock and key theory and induced fit model... Show more
Induced Fit Model and Reaction Rates
Induced Fit Model
The induced fit model of enzyme action is an extension of the lock and key theory. This model proposes that the enzyme's active site is more flexible than initially thought.
Definition: The induced fit model suggests that the enzyme changes its shape slightly to fit the substrate better during the reaction process.
This model provides a more accurate representation of enzyme-substrate interactions, accounting for the dynamic nature of protein structures.
Factors Affecting Enzyme Activity
Temperature
Temperature significantly impacts enzyme activity. Each enzyme has an optimum temperature at which it functions best.
Vocabulary: Optimum temperature is the temperature at which an enzyme functions most efficiently.
Highlight: If the temperature exceeds the optimum, the enzyme's shape starts to change, and it becomes denatured, rendering it inactive.
pH
The pH level also plays a crucial role in enzyme activity. Each enzyme has an optimum pH at which it performs most effectively.
Vocabulary: Optimum pH is the pH level at which the enzyme functions best.
Highlight: If the pH surpasses the optimum level, the enzyme will change shape, slowing down the rate of reaction and potentially becoming denatured.
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Calculating Enzyme Reaction Rates
Understanding how to calculate enzyme reaction rates is crucial in biochemistry and molecular biology. This knowledge allows scientists to quantify enzyme activity and compare the efficiency of different enzymes or the same enzyme under various conditions.
Formula for Reaction Rate
The rate of an enzyme-catalyzed reaction can be calculated using the following formula:
Rate of Reaction = Change in Product / Time Taken
Example: If an enzyme-controlled reaction produces 30 cm³ of hydrogen gas in 2 minutes, the rate of reaction would be: 30 cm³ / 120 seconds = 0.25 cm³/s
Units of Measurement
When calculating enzyme reaction rates, it's important to use consistent units:
- Change in product: Typically measured in cubic centimeters (cm³)
- Time taken: Usually measured in seconds (s)
- Rate of reaction: Often expressed as cubic centimeters per second (cm³/s)
Highlight: Proper unit conversion is crucial when calculating enzyme reaction rates to ensure accurate results.
Understanding these concepts and calculations is essential for students studying biology, biochemistry, or related fields. It provides a foundation for more advanced studies in enzyme kinetics and metabolic processes.
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Enzymes: Structure and Function
Enzymes are essential biological catalysts that increase reaction rates without being consumed in the process. They are large proteins composed of amino acids and have specific active sites that bind to substrates.
Definition: An enzyme is a biological catalyst that increases the rate of reaction without being changed or used in the process.
Vocabulary:
- Substrate: The substance on which an enzyme reacts.
- Active site: A surface on the enzyme that only allows it to bind with certain substrates.
Lock and Key Theory
The lock and key theory in enzymes explains how enzymes and substrates interact. This model suggests that the active site of an enzyme has a specific shape that perfectly complements the shape of its substrate, much like a key fits into a lock.
Example: The lock and key model process involves:
- The substrate colliding with and attaching to the enzyme's active site.
- The enzyme catalyzing the breakdown of the substrate.
- The products being released from the active site.
Highlight: The enzyme molecule remains unchanged after the reaction and can be reused, making it an efficient catalyst.
We thought you’d never ask...
What is the Knowunity AI companion?
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.
Where can I download the Knowunity app?
You can download the app from Google Play Store and Apple App Store.
Is Knowunity really free of charge?
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
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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