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Lucy
10/11/2022
Biology
AQA A level biology Respiration notes
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10 Nov 2022
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AQA A Level Biology Respiration Notes - PDF Download and Exam Questions
Lucy
@lucy_sldh
The Link Reaction and Krebs Cycle
The link reaction and Krebs cycle are essential components of aerobic respiration, occurring in the mitochondria when oxygen is present.
The link reaction connects glycolysis to the Krebs cycle:
- Pyruvate enters the mitochondrial matrix via active transport
- Pyruvate is oxidized to form acetate, producing reduced NAD and releasing CO2
- Acetate combines with coenzyme A to form acetyl coenzyme A
The Krebs cycle takes place in the mitochondrial matrix:
- Acetyl coenzyme A enters the cycle
- Through a series of redox reactions, 3 reduced NAD, 1 reduced FAD, and ATP are generated
- CO2 is released as a byproduct
Definition: Redox reaction - A chemical reaction involving the transfer of electrons between species, resulting in changes in oxidation states.
Understanding these processes is vital for success in respiration A-level biology AQA examinations and for mastering glycolysis A-level biology concepts.
Oxidative Phosphorylation: The Final Stage of Aerobic Respiration
Oxidative phosphorylation is the culminating stage of aerobic respiration, occurring in the inner mitochondrial membrane. This process generates the majority of ATP molecules and produces water as a byproduct.
The key steps of oxidative phosphorylation include:
- Donation of hydrogen atoms from reduced NAD and FAD
- Splitting of hydrogen atoms into ions and electrons
- Electron transport chain energy release
- Active transport of hydrogen ions to create a concentration gradient
- Facilitated diffusion of protons through ATP synthase, driving ATP production
- Oxygen acting as the final electron acceptor, forming water
Example: The electron transport chain can be likened to a series of waterfalls, with electrons losing energy at each step, which is then harnessed to pump protons across the membrane.
This detailed explanation of oxidative phosphorylation is essential for students preparing AQA A-level biology respiration revision PDF materials and tackling respiration A-level biology questions.
Anaerobic Respiration in Animals and Plants
Anaerobic respiration occurs when cells have limited or no oxygen available. The process differs between animals and plants.
In animals:
- Glucose is converted to pyruvate through glycolysis
- Pyruvate is then reduced to lactate, regenerating NAD
- Lactate can be later oxidized back to pyruvate or converted to glycogen for storage
In plants:
- Glucose is converted to pyruvate through glycolysis
- Pyruvate is decarboxylated to ethanal, producing CO2
- Ethanal is reduced to ethanol by alcohol dehydrogenase, regenerating NAD
Highlight: The key difference in anaerobic respiration between animals and plants is the end product: lactate in animals and ethanol in plants.
Understanding these processes is crucial for students studying anaerobic respiration A-level biology and preparing for respiration AQA A-level biology exam questions.
Page 5: Anaerobic Respiration in Plants
The final page focuses on anaerobic respiration in plants, detailing the production of ethanol from glucose via pyruvate and ethanal.
Vocabulary:
- Ethanal: An intermediate compound in plant anaerobic respiration
- Alcohol dehydrogenase: The enzyme that converts ethanal to ethanol
Highlight: This content is essential for respiration a level biology aqa exam preparation, particularly regarding the differences between plant and animal anaerobic respiration.
Glycolysis: The First Stage of Respiration
Glycolysis is the initial step in both aerobic and anaerobic respiration, occurring in the cell's cytoplasm. This process breaks down glucose into pyruvate, generating a small amount of ATP and reduced NAD.
Highlight: Glycolysis yields a net gain of two ATP molecules and two reduced NAD molecules.
The process of glycolysis involves several key steps:
- Phosphorylation of glucose using 2 ATP molecules
- Splitting of the unstable phosphorylated glucose into two 3-carbon triose phosphate molecules
- Oxidation of triose phosphate to form pyruvate, producing 4 ATP and 2 NADH
Vocabulary: Phosphorylation - The addition of a phosphate group to a molecule, often using energy from ATP.
This detailed understanding of glycolysis is crucial for students studying A-level biology respiration notes PDF and preparing for AQA A-level biology respiration exam questions.
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Thomas R
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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.
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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.
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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.
Rohan U
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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.
Xander S
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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
AQA A Level Biology Respiration Notes - PDF Download and Exam Questions
Lucy
@lucy_sldh
Cellular Respiration in Biology: A Comprehensive Guide - A detailed exploration of both aerobic and anaerobic respiration processes, covering glycolysis, the link reaction, Krebs cycle, and oxidative phosphorylation.
Key points:
- Glycolysisoccurs in the cytoplasm and is common to both... Show more
The Link Reaction and Krebs Cycle
The link reaction and Krebs cycle are essential components of aerobic respiration, occurring in the mitochondria when oxygen is present.
The link reaction connects glycolysis to the Krebs cycle:
- Pyruvate enters the mitochondrial matrix via active transport
- Pyruvate is oxidized to form acetate, producing reduced NAD and releasing CO2
- Acetate combines with coenzyme A to form acetyl coenzyme A
The Krebs cycle takes place in the mitochondrial matrix:
- Acetyl coenzyme A enters the cycle
- Through a series of redox reactions, 3 reduced NAD, 1 reduced FAD, and ATP are generated
- CO2 is released as a byproduct
Definition: Redox reaction - A chemical reaction involving the transfer of electrons between species, resulting in changes in oxidation states.
Understanding these processes is vital for success in respiration A-level biology AQA examinations and for mastering glycolysis A-level biology concepts.
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Oxidative Phosphorylation: The Final Stage of Aerobic Respiration
Oxidative phosphorylation is the culminating stage of aerobic respiration, occurring in the inner mitochondrial membrane. This process generates the majority of ATP molecules and produces water as a byproduct.
The key steps of oxidative phosphorylation include:
- Donation of hydrogen atoms from reduced NAD and FAD
- Splitting of hydrogen atoms into ions and electrons
- Electron transport chain energy release
- Active transport of hydrogen ions to create a concentration gradient
- Facilitated diffusion of protons through ATP synthase, driving ATP production
- Oxygen acting as the final electron acceptor, forming water
Example: The electron transport chain can be likened to a series of waterfalls, with electrons losing energy at each step, which is then harnessed to pump protons across the membrane.
This detailed explanation of oxidative phosphorylation is essential for students preparing AQA A-level biology respiration revision PDF materials and tackling respiration A-level biology questions.
Anaerobic Respiration in Animals and Plants
Anaerobic respiration occurs when cells have limited or no oxygen available. The process differs between animals and plants.
In animals:
- Glucose is converted to pyruvate through glycolysis
- Pyruvate is then reduced to lactate, regenerating NAD
- Lactate can be later oxidized back to pyruvate or converted to glycogen for storage
In plants:
- Glucose is converted to pyruvate through glycolysis
- Pyruvate is decarboxylated to ethanal, producing CO2
- Ethanal is reduced to ethanol by alcohol dehydrogenase, regenerating NAD
Highlight: The key difference in anaerobic respiration between animals and plants is the end product: lactate in animals and ethanol in plants.
Understanding these processes is crucial for students studying anaerobic respiration A-level biology and preparing for respiration AQA A-level biology exam questions.
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Page 5: Anaerobic Respiration in Plants
The final page focuses on anaerobic respiration in plants, detailing the production of ethanol from glucose via pyruvate and ethanal.
Vocabulary:
- Ethanal: An intermediate compound in plant anaerobic respiration
- Alcohol dehydrogenase: The enzyme that converts ethanal to ethanol
Highlight: This content is essential for respiration a level biology aqa exam preparation, particularly regarding the differences between plant and animal anaerobic respiration.
Glycolysis: The First Stage of Respiration
Glycolysis is the initial step in both aerobic and anaerobic respiration, occurring in the cell's cytoplasm. This process breaks down glucose into pyruvate, generating a small amount of ATP and reduced NAD.
Highlight: Glycolysis yields a net gain of two ATP molecules and two reduced NAD molecules.
The process of glycolysis involves several key steps:
- Phosphorylation of glucose using 2 ATP molecules
- Splitting of the unstable phosphorylated glucose into two 3-carbon triose phosphate molecules
- Oxidation of triose phosphate to form pyruvate, producing 4 ATP and 2 NADH
Vocabulary: Phosphorylation - The addition of a phosphate group to a molecule, often using energy from ATP.
This detailed understanding of glycolysis is crucial for students studying A-level biology respiration notes PDF and preparing for AQA A-level biology respiration exam questions.
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.
Can't find what you're looking for? Explore other subjects.
Students love us — and so will you.
4.9/5
App Store
4.8/5
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