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Britain & the wider world: 1745 -1901
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Biology
10 Dec 2025
757
3 pages
Every breath you take fuels an incredible chemical reaction happening inside your cells right now. Cellular respirationis... Show more
Your body needs energy for everything - from thinking about your next TikTok post to running for the bus. Cellular respiration is the chemical process that releases this energy from food, particularly glucose (sugar). This reaction is actually endothermic, meaning it releases energy to your surroundings - that's why you feel warm when you exercise!
The energy produced is stored in a special molecule called ATP (adenosine triphosphate). Think of ATP as your body's rechargeable battery - it stores energy and releases it whenever your cells need power.
Aerobic respiration is the main type that requires oxygen to work. Your body takes glucose (the respiratory substrate) and oxidises it, which basically means adding oxygen to break it down and unlock its stored energy.
Quick Tip Remember that oxidation can happen by adding oxygen, removing hydrogen, or removing electrons - it's all about breaking down molecules to release energy!
The chemical equation for aerobic respiration might look scary, but it's actually quite straightforward. In simple terms glucose plus oxygen creates carbon dioxide, water, and loads of energy.
The balanced symbol equation is C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O. Notice how everything balances out perfectly - you get 6 molecules of carbon dioxide and 6 molecules of water from one glucose molecule and 6 oxygen molecules.
But what happens when there's no oxygen available? Your body switches to anaerobic respiration instead. This process doesn't need oxygen, but there's a catch - it produces much less energy because the oxidation is incomplete.
During intense exercise, when your muscles can't get enough oxygen, they use anaerobic respiration. The downside? It produces lactic acid, which causes that burning sensation in your muscles after a sprint!
Remember Anaerobic respiration is your body's emergency backup system when oxygen runs low!
Fermentation is basically anaerobic respiration in fungi like yeast, and it's incredibly useful for humans. When yeast breaks down glucose without oxygen, it produces ethanol (alcohol) and carbon dioxide instead of lactic acid.
The equation is beautifully simple Glucose → Ethanol + Carbon dioxide. This process is how we make bread (the CO₂ makes dough rise), alcoholic drinks (the ethanol is the alcohol), and even biofuels.
Next time you see bread rising or beer bubbling, you're watching millions of yeast cells doing fermentation. They're essentially getting drunk on sugar whilst producing the alcohol we use!
Fun Fact The bubbles in champagne and the fluffiness of bread both come from the same process - yeast fermentation!
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.
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Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Explore the essential processes of Cellular Respiration, including Glycolysis, Krebs Cycle, and the Electron Transport Chain. Understand how ATP is produced through aerobic and anaerobic pathways, and the role of oxygen in energy metabolism. This summary provides a clear insight into cellular bioenergetics and oxidative phosphorylation.
BiologyExplore the essential processes of aerobic respiration, including the chemical equation, the role of oxygen, and the significance of by-products like carbon dioxide and water. This summary covers key concepts such as cellular bioenergetics and the differences between respiration and breathing, making it ideal for GCSE Biology students.
BiologyExplore the mechanisms of gas exchange in humans and plants, including the role of alveoli and spongy mesophyll. Understand aerobic and anaerobic respiration processes, their equations, and practical experiments. This summary is essential for CCEA GCSE Biology students focusing on cellular energetics and respiratory systems.
BiologyExplore the process of aerobic respiration in mitochondria, including ATP production, energy transfer, and the role of glucose in cellular activities. This summary covers key concepts such as muscle cell energy requirements, glycolysis, and fermentation, making it essential for Nat 5 Biology students.
BiologyExplore the processes of aerobic and anaerobic respiration, including energy production, the role of enzymes, and the impact of exercise on muscle function. This summary covers key concepts such as ATP production, glucose breakdown, and the physiological changes during physical activity. Ideal for students studying biology and cellular metabolism.
BiologyExplore the physiological effects of exercise on respiration, including aerobic and anaerobic processes, oxygen debt, and muscle fatigue. This summary covers key concepts such as energy demands during physical activity, the role of lactic acid, and the importance of respiration in cellular metabolism. Ideal for AQA GCSE Biology students.
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
Every breath you take fuels an incredible chemical reaction happening inside your cells right now. Cellular respiration is the process that converts the food you eat into usable energy, keeping you alive and moving throughout the day.
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Your body needs energy for everything - from thinking about your next TikTok post to running for the bus. Cellular respiration is the chemical process that releases this energy from food, particularly glucose (sugar). This reaction is actually endothermic, meaning it releases energy to your surroundings - that's why you feel warm when you exercise!
The energy produced is stored in a special molecule called ATP (adenosine triphosphate). Think of ATP as your body's rechargeable battery - it stores energy and releases it whenever your cells need power.
Aerobic respiration is the main type that requires oxygen to work. Your body takes glucose (the respiratory substrate) and oxidises it, which basically means adding oxygen to break it down and unlock its stored energy.
Quick Tip: Remember that oxidation can happen by adding oxygen, removing hydrogen, or removing electrons - it's all about breaking down molecules to release energy!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
The chemical equation for aerobic respiration might look scary, but it's actually quite straightforward. In simple terms: glucose plus oxygen creates carbon dioxide, water, and loads of energy.
The balanced symbol equation is: C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O. Notice how everything balances out perfectly - you get 6 molecules of carbon dioxide and 6 molecules of water from one glucose molecule and 6 oxygen molecules.
But what happens when there's no oxygen available? Your body switches to anaerobic respiration instead. This process doesn't need oxygen, but there's a catch - it produces much less energy because the oxidation is incomplete.
During intense exercise, when your muscles can't get enough oxygen, they use anaerobic respiration. The downside? It produces lactic acid, which causes that burning sensation in your muscles after a sprint!
Remember: Anaerobic respiration is your body's emergency backup system when oxygen runs low!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Fermentation is basically anaerobic respiration in fungi like yeast, and it's incredibly useful for humans. When yeast breaks down glucose without oxygen, it produces ethanol (alcohol) and carbon dioxide instead of lactic acid.
The equation is beautifully simple: Glucose → Ethanol + Carbon dioxide. This process is how we make bread (the CO₂ makes dough rise), alcoholic drinks (the ethanol is the alcohol), and even biofuels.
Next time you see bread rising or beer bubbling, you're watching millions of yeast cells doing fermentation. They're essentially getting drunk on sugar whilst producing the alcohol we use!
Fun Fact: The bubbles in champagne and the fluffiness of bread both come from the same process - yeast fermentation!
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.
8
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Explore the essential processes of Cellular Respiration, including Glycolysis, Krebs Cycle, and the Electron Transport Chain. Understand how ATP is produced through aerobic and anaerobic pathways, and the role of oxygen in energy metabolism. This summary provides a clear insight into cellular bioenergetics and oxidative phosphorylation.
BiologyExplore the essential processes of aerobic respiration, including the chemical equation, the role of oxygen, and the significance of by-products like carbon dioxide and water. This summary covers key concepts such as cellular bioenergetics and the differences between respiration and breathing, making it ideal for GCSE Biology students.
BiologyExplore the mechanisms of gas exchange in humans and plants, including the role of alveoli and spongy mesophyll. Understand aerobic and anaerobic respiration processes, their equations, and practical experiments. This summary is essential for CCEA GCSE Biology students focusing on cellular energetics and respiratory systems.
BiologyExplore the process of aerobic respiration in mitochondria, including ATP production, energy transfer, and the role of glucose in cellular activities. This summary covers key concepts such as muscle cell energy requirements, glycolysis, and fermentation, making it essential for Nat 5 Biology students.
BiologyExplore the processes of aerobic and anaerobic respiration, including energy production, the role of enzymes, and the impact of exercise on muscle function. This summary covers key concepts such as ATP production, glucose breakdown, and the physiological changes during physical activity. Ideal for students studying biology and cellular metabolism.
BiologyExplore the physiological effects of exercise on respiration, including aerobic and anaerobic processes, oxygen debt, and muscle fatigue. This summary covers key concepts such as energy demands during physical activity, the role of lactic acid, and the importance of respiration in cellular metabolism. Ideal for AQA GCSE Biology students.
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
Sociology