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18 Jan 2026
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Understanding Bioenergetics: Definitions and Formulas Explained
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Photosynthesis: Nature's Solar Panels
Think of photosynthesis as nature's way of turning sunlight into food. Plants, algae, and some bacteria are brilliant at this - they capture light energy and convert it into glucose (sugar) that stores chemical energy.
This amazing process happens in chloroplasts, tiny green structures in plant cells that contain chlorophyll - the pigment that makes plants green and captures light. The overall equation is dead simple: carbon dioxide + water + light energy → glucose + oxygen.
Photosynthesis has two main stages. The light-dependent reactions happen in special membranes where chlorophyll gets excited by light and splits water molecules, releasing oxygen as a bonus. Then the Calvin cycle uses carbon dioxide to actually build glucose molecules.
Quick Tip: Remember that the oxygen you breathe is literally a waste product from plants making their lunch!
Three main factors can limit how fast photosynthesis happens: light intensity, carbon dioxide concentration, and temperature. If any of these are too low (or temperature's too high), the whole process slows down.
Respiration: Breaking Down for Energy
While photosynthesis builds glucose up, respiration breaks it down to release energy. Every living cell does this constantly - it's how your body powers everything from thinking to moving your muscles.
Aerobic respiration needs oxygen and happens in the mitochondria (the cell's powerhouses). It's super efficient and releases loads of ATP - the energy currency cells actually use. Anaerobic respiration happens without oxygen, but it's much less efficient and can produce lactic acid in your muscles.
Your body uses this energy for three main things: movement (muscle contraction), synthesis (building proteins and other molecules), and homeostasis (keeping your body temperature steady). Pretty much everything you do depends on respiration working properly.
Metabolism is just the fancy name for all these chemical reactions happening in your body. Some reactions break things down (catabolic), whilst others build things up (anabolic).
Exercise, Fermentation, and Energy Demands
When you exercise, your muscles desperately need more energy, so your breathing and heart rate shoot up. If you can't get enough oxygen to your muscles, they switch to anaerobic respiration and start producing lactic acid - that's what makes your muscles burn and feel tired.
After intense exercise, you'll keep breathing heavily to pay back the oxygen debt. Your body needs extra oxygen to clear out all that lactic acid by converting it back to carbon dioxide and water.
Fermentation is basically anaerobic respiration in microorganisms like yeast. This process is actually dead useful - yeast ferments sugars to make carbon dioxide (which makes bread rise) or ethanol (which makes alcoholic drinks).
Did You Know: The bubbles in bread and the alcohol in beer both come from the same basic process - yeast running out of oxygen!
Understanding these processes helps explain why you get out of breath, why bread rises, and how your body recovers after a workout.
Photosynthesis vs Respiration: The Perfect Partnership
Photosynthesis and respiration are basically opposite processes that work together beautifully. Photosynthesis happens in chloroplasts and builds glucose using light energy, whilst respiration happens in mitochondria and breaks glucose down for energy.
Plants do both processes, but all living organisms (including you) do respiration. The oxygen plants release during photosynthesis is exactly what animals need for aerobic respiration - and the carbon dioxide we breathe out is what plants need for photosynthesis.
Plants store their glucose as starch, whilst animals store theirs as glycogen. Both can be broken down quickly when energy's needed. Plants also use glucose to make cellulose for strong cell walls and combine it with nutrients to build amino acids.
These processes are absolutely fundamental to life on Earth. Without photosynthesis, there'd be no oxygen in the atmosphere and no food chains. Without respiration, nothing could actually use the energy that's stored in food molecules.
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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.
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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.
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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.
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THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE Knowunity AI. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
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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 Knowunity AI. 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
Understanding Bioenergetics: Definitions and Formulas Explained
Ever wondered how plants make their own food whilst you need to raid the fridge? Bioenergeticsis all about how living things capture, store, and use energy to survive. From the oxygen you breathe to the energy powering your muscles... Show more
Photosynthesis: Nature's Solar Panels
Think of photosynthesis as nature's way of turning sunlight into food. Plants, algae, and some bacteria are brilliant at this - they capture light energy and convert it into glucose (sugar) that stores chemical energy.
This amazing process happens in chloroplasts, tiny green structures in plant cells that contain chlorophyll - the pigment that makes plants green and captures light. The overall equation is dead simple: carbon dioxide + water + light energy → glucose + oxygen.
Photosynthesis has two main stages. The light-dependent reactions happen in special membranes where chlorophyll gets excited by light and splits water molecules, releasing oxygen as a bonus. Then the Calvin cycle uses carbon dioxide to actually build glucose molecules.
Quick Tip: Remember that the oxygen you breathe is literally a waste product from plants making their lunch!
Three main factors can limit how fast photosynthesis happens: light intensity, carbon dioxide concentration, and temperature. If any of these are too low (or temperature's too high), the whole process slows down.
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Respiration: Breaking Down for Energy
While photosynthesis builds glucose up, respiration breaks it down to release energy. Every living cell does this constantly - it's how your body powers everything from thinking to moving your muscles.
Aerobic respiration needs oxygen and happens in the mitochondria (the cell's powerhouses). It's super efficient and releases loads of ATP - the energy currency cells actually use. Anaerobic respiration happens without oxygen, but it's much less efficient and can produce lactic acid in your muscles.
Your body uses this energy for three main things: movement (muscle contraction), synthesis (building proteins and other molecules), and homeostasis (keeping your body temperature steady). Pretty much everything you do depends on respiration working properly.
Metabolism is just the fancy name for all these chemical reactions happening in your body. Some reactions break things down (catabolic), whilst others build things up (anabolic).
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Exercise, Fermentation, and Energy Demands
When you exercise, your muscles desperately need more energy, so your breathing and heart rate shoot up. If you can't get enough oxygen to your muscles, they switch to anaerobic respiration and start producing lactic acid - that's what makes your muscles burn and feel tired.
After intense exercise, you'll keep breathing heavily to pay back the oxygen debt. Your body needs extra oxygen to clear out all that lactic acid by converting it back to carbon dioxide and water.
Fermentation is basically anaerobic respiration in microorganisms like yeast. This process is actually dead useful - yeast ferments sugars to make carbon dioxide (which makes bread rise) or ethanol (which makes alcoholic drinks).
Did You Know: The bubbles in bread and the alcohol in beer both come from the same basic process - yeast running out of oxygen!
Understanding these processes helps explain why you get out of breath, why bread rises, and how your body recovers after a workout.
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Photosynthesis vs Respiration: The Perfect Partnership
Photosynthesis and respiration are basically opposite processes that work together beautifully. Photosynthesis happens in chloroplasts and builds glucose using light energy, whilst respiration happens in mitochondria and breaks glucose down for energy.
Plants do both processes, but all living organisms (including you) do respiration. The oxygen plants release during photosynthesis is exactly what animals need for aerobic respiration - and the carbon dioxide we breathe out is what plants need for photosynthesis.
Plants store their glucose as starch, whilst animals store theirs as glycogen. Both can be broken down quickly when energy's needed. Plants also use glucose to make cellulose for strong cell walls and combine it with nutrients to build amino acids.
These processes are absolutely fundamental to life on Earth. Without photosynthesis, there'd be no oxygen in the atmosphere and no food chains. Without respiration, nothing could actually use the energy that's stored in food molecules.
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?
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Is Knowunity really free of charge?
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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 Knowunity AI. 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 Knowunity AI. 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