Cellular respiration is the process that cells use to convert... Show more
Algebra
Calculus 1
Algebra 1
OverigeSign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
1 / 4
Cellular Respiration Basics
Ever wonder why you get out of breath during intense exercise? Your muscle cells switch to "emergency mode" when they exceed their aerobic capacity, breaking down glucose inefficiently and producing lactic acid as a byproduct.
Energy flows through the biosphere in a remarkable cycle. It typically begins with the sun, where plants and other autotrophs convert sunlight into chemical energy through photosynthesis. These organisms are called producers because they produce their own food from inorganic molecules.
Humans and other animals are heterotrophs, meaning we must obtain energy by consuming plants or animals that have eaten plants. We can't create organic molecules from inorganic ones like plants can, which is why biologists refer to us as consumers.
Quick Fact: Cellular respiration forms a perfect chemical cycle with photosynthesis. Plants produce oxygen and glucose through photosynthesis, while animals consume oxygen and glucose during cellular respiration, producing carbon dioxide that plants use.
The overall equation for cellular respiration shows that glucose (C₆H₁₂O₆) serves as the primary fuel. This sugar molecule stores an enormous amount of energy that must be released carefully through a controlled series of reactions.
How Cellular Respiration Works
Cellular respiration is like a controlled demolition of glucose. Instead of releasing all the energy at once (which would be dangerous), specialized enzymes break it down step by step, capturing the released energy in ATP molecules.
As enzymes react with glucose (C₆H₁₂O₆), the six carbon atoms are separated and released as carbon dioxide (CO₂) waste. During this process, hydrogen atoms and their electrons change partners, moving from sugar to oxygen and forming water.
The entire cellular respiration pathway consists of three main stages:
-
Glycolysis - Occurs in the cytosol (cell fluid)
- Splits 6-carbon glucose into two 3-carbon pyruvic acids
- Produces 2 ATP and 2 NADH molecules
-
Citric Acid Cycle - Takes place in the mitochondrial matrix
- Completes the breakdown of pyruvic acids into carbon dioxide (this is the CO₂ you exhale!)
- Generates 2 ATP and 8 NADH molecules
Remember This: The electron transport chain is where most of your ATP is made. This is why oxygen is so critical—without it, this energy-producing superhighway shuts down!
- Electron Transport Chain - Located in the inner mitochondrial membrane
- Converts the 10 NADH from earlier stages into 28 ATP
- Requires oxygen as the final electron acceptor, creating water
Fermentation and Gas Exchange
When oxygen isn't available, some cells can temporarily switch to fermentation—an anaerobic (without oxygen) process for harvesting food energy. After about 15 seconds without oxygen, electron transport stops, NADH accumulates, and fermentation kicks in to produce just 2 ATP per glucose molecule.
Fermentation works differently across species. In yeast cells, it produces carbon dioxide and alcohol (yes, the same alcohol in beverages!). In human muscle cells, fermentation creates lactic acid instead. Unfortunately, our brain cells cannot perform fermentation, making them the first to die when oxygen is unavailable.
Two body systems work together to support cellular respiration. The respiratory system exchanges gases with the environment, bringing in oxygen and removing carbon dioxide. The circulatory system then transports these gases between the lungs and all the cells in your body.
Health Connection: High blood pressure (hypertension) often develops when blood vessels narrow due to cholesterol plaques, forcing your heart to work harder to push blood through these constricted passages.
Cardiovascular disease develops when atherosclerosis (plaque buildup) progresses. Blood clots can form around these plaques, completely blocking blood flow. When blockages occur in coronary arteries that supply oxygen to the heart muscle, a heart attack results. Similar blockages in brain blood vessels cause strokes.
Cardiovascular Health and Cellular Respiration
Atherosclerosis doesn't just happen overnight—it develops gradually as plaques form and grow within blood vessel walls. These fatty deposits narrow the passageways that blood must flow through, increasing resistance and raising blood pressure.
When blood clots form around these plaques, they can completely stop blood flow to critical tissues. A blockage in the coronary arteries that supply oxygen to the heart muscle causes a heart attack, while blockages in brain blood vessels lead to strokes, both potentially life-threatening conditions.
The connection between cellular respiration and cardiovascular health is clear: your cells need a constant supply of oxygen and nutrients to produce ATP through aerobic respiration. Any compromise to this delivery system can have serious consequences for cellular function and survival.
Take Action: Regular exercise helps strengthen your cardiovascular system, improving oxygen delivery to your cells and making cellular respiration more efficient throughout your body.
We thought you’d never ask...
What is the Knowunity AI companion?
Our AI companion is specifically built for the needs of students. Based on the millions of content pieces we have on the platform we can provide truly meaningful and relevant answers to students. But its not only about answers, the companion is even more about guiding students through their daily learning challenges, with personalised study plans, quizzes or content pieces in the chat and 100% personalisation based on the students skills and developments.
Where can I download the Knowunity app?
You can download the app in the Google Play Store and in the 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.
Most popular content: Cellular Respiration
Most popular content in AP Biology
Most popular content
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
I think it’s very much worth it and you’ll end up using it a lot once you get the hang of it and even after looking at others notes you can still ask your Artificial intelligence buddy the question and ask to simplify it if you still don’t get it!!! In the end I think it’s worth it 😊👍 ⚠️Also DID I MENTION ITS FREEE YOU DON’T HAVE TO PAY FOR ANYTHING AND STILL GET YOUR GRADES IN PERFECTLY❗️❗️⚠️
Thomas R
iOS user
Knowunity is the BEST app I’ve used in a minute. This is not an ai review or anything this is genuinely coming from a 7th grade student (I know 2011 im young) but dude this app is a 10/10 i have maintained a 3.8 gpa and have plenty of time for gaming. I love it and my mom is just happy I got good grades
Brad T
Android user
Not only did it help me find the answer but it also showed me alternative ways to solve it. I was horrible in math and science but now I have an a in both subjects. Thanks for the help🤍🤍
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
I found this app a couple years ago and it has only gotten better since then. I really love it because it can help with written questions and photo questions. Also, it can find study guides that other people have made as well as flashcard sets and practice tests. The free version is also amazing for students who might not be able to afford it. Would 100% recommend
Aubrey
iOS user
Best app if you're in Highschool or Junior high. I have been using this app for 2 school years and it's the best, it's good if you don't have anyone to help you with school work.😋🩷🎀
Marco B
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 app is phenomenal down to the correct info and the various topics you can study! I greatly recommend it for people who struggle with procrastination and those who need homework help. It has been perfectly accurate for world 1 history as far as I’ve seen! Geometry too!
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
I think it’s very much worth it and you’ll end up using it a lot once you get the hang of it and even after looking at others notes you can still ask your Artificial intelligence buddy the question and ask to simplify it if you still don’t get it!!! In the end I think it’s worth it 😊👍 ⚠️Also DID I MENTION ITS FREEE YOU DON’T HAVE TO PAY FOR ANYTHING AND STILL GET YOUR GRADES IN PERFECTLY❗️❗️⚠️
Thomas R
iOS user
Knowunity is the BEST app I’ve used in a minute. This is not an ai review or anything this is genuinely coming from a 7th grade student (I know 2011 im young) but dude this app is a 10/10 i have maintained a 3.8 gpa and have plenty of time for gaming. I love it and my mom is just happy I got good grades
Brad T
Android user
Not only did it help me find the answer but it also showed me alternative ways to solve it. I was horrible in math and science but now I have an a in both subjects. Thanks for the help🤍🤍
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
I found this app a couple years ago and it has only gotten better since then. I really love it because it can help with written questions and photo questions. Also, it can find study guides that other people have made as well as flashcard sets and practice tests. The free version is also amazing for students who might not be able to afford it. Would 100% recommend
Aubrey
iOS user
Best app if you're in Highschool or Junior high. I have been using this app for 2 school years and it's the best, it's good if you don't have anyone to help you with school work.😋🩷🎀
Marco B
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 app is phenomenal down to the correct info and the various topics you can study! I greatly recommend it for people who struggle with procrastination and those who need homework help. It has been perfectly accurate for world 1 history as far as I’ve seen! Geometry too!
Paul T
iOS user
Cellular Respiration Step-by-Step Guide
Cellular respiration is the process that cells use to convert the energy in food into ATP, the energy currency they can actually use. This essential biochemical pathway breaks down glucose molecules, releasing stored energy while producing carbon dioxide and water... Show more
Cellular Respiration Basics
Ever wonder why you get out of breath during intense exercise? Your muscle cells switch to "emergency mode" when they exceed their aerobic capacity, breaking down glucose inefficiently and producing lactic acid as a byproduct.
Energy flows through the biosphere in a remarkable cycle. It typically begins with the sun, where plants and other autotrophs convert sunlight into chemical energy through photosynthesis. These organisms are called producers because they produce their own food from inorganic molecules.
Humans and other animals are heterotrophs, meaning we must obtain energy by consuming plants or animals that have eaten plants. We can't create organic molecules from inorganic ones like plants can, which is why biologists refer to us as consumers.
Quick Fact: Cellular respiration forms a perfect chemical cycle with photosynthesis. Plants produce oxygen and glucose through photosynthesis, while animals consume oxygen and glucose during cellular respiration, producing carbon dioxide that plants use.
The overall equation for cellular respiration shows that glucose (C₆H₁₂O₆) serves as the primary fuel. This sugar molecule stores an enormous amount of energy that must be released carefully through a controlled series of reactions.
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
How Cellular Respiration Works
Cellular respiration is like a controlled demolition of glucose. Instead of releasing all the energy at once (which would be dangerous), specialized enzymes break it down step by step, capturing the released energy in ATP molecules.
As enzymes react with glucose (C₆H₁₂O₆), the six carbon atoms are separated and released as carbon dioxide (CO₂) waste. During this process, hydrogen atoms and their electrons change partners, moving from sugar to oxygen and forming water.
The entire cellular respiration pathway consists of three main stages:
-
Glycolysis - Occurs in the cytosol (cell fluid)
- Splits 6-carbon glucose into two 3-carbon pyruvic acids
- Produces 2 ATP and 2 NADH molecules
-
Citric Acid Cycle - Takes place in the mitochondrial matrix
- Completes the breakdown of pyruvic acids into carbon dioxide (this is the CO₂ you exhale!)
- Generates 2 ATP and 8 NADH molecules
Remember This: The electron transport chain is where most of your ATP is made. This is why oxygen is so critical—without it, this energy-producing superhighway shuts down!
- Electron Transport Chain - Located in the inner mitochondrial membrane
- Converts the 10 NADH from earlier stages into 28 ATP
- Requires oxygen as the final electron acceptor, creating water
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Fermentation and Gas Exchange
When oxygen isn't available, some cells can temporarily switch to fermentation—an anaerobic (without oxygen) process for harvesting food energy. After about 15 seconds without oxygen, electron transport stops, NADH accumulates, and fermentation kicks in to produce just 2 ATP per glucose molecule.
Fermentation works differently across species. In yeast cells, it produces carbon dioxide and alcohol (yes, the same alcohol in beverages!). In human muscle cells, fermentation creates lactic acid instead. Unfortunately, our brain cells cannot perform fermentation, making them the first to die when oxygen is unavailable.
Two body systems work together to support cellular respiration. The respiratory system exchanges gases with the environment, bringing in oxygen and removing carbon dioxide. The circulatory system then transports these gases between the lungs and all the cells in your body.
Health Connection: High blood pressure (hypertension) often develops when blood vessels narrow due to cholesterol plaques, forcing your heart to work harder to push blood through these constricted passages.
Cardiovascular disease develops when atherosclerosis (plaque buildup) progresses. Blood clots can form around these plaques, completely blocking blood flow. When blockages occur in coronary arteries that supply oxygen to the heart muscle, a heart attack results. Similar blockages in brain blood vessels cause strokes.
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Cardiovascular Health and Cellular Respiration
Atherosclerosis doesn't just happen overnight—it develops gradually as plaques form and grow within blood vessel walls. These fatty deposits narrow the passageways that blood must flow through, increasing resistance and raising blood pressure.
When blood clots form around these plaques, they can completely stop blood flow to critical tissues. A blockage in the coronary arteries that supply oxygen to the heart muscle causes a heart attack, while blockages in brain blood vessels lead to strokes, both potentially life-threatening conditions.
The connection between cellular respiration and cardiovascular health is clear: your cells need a constant supply of oxygen and nutrients to produce ATP through aerobic respiration. Any compromise to this delivery system can have serious consequences for cellular function and survival.
Take Action: Regular exercise helps strengthen your cardiovascular system, improving oxygen delivery to your cells and making cellular respiration more efficient throughout your body.
We thought you’d never ask...
What is the Knowunity AI companion?
Our AI companion is specifically built for the needs of students. Based on the millions of content pieces we have on the platform we can provide truly meaningful and relevant answers to students. But its not only about answers, the companion is even more about guiding students through their daily learning challenges, with personalised study plans, quizzes or content pieces in the chat and 100% personalisation based on the students skills and developments.
Where can I download the Knowunity app?
You can download the app in the Google Play Store and in the 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.
8
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Mock Exam
Quiz
Flashcards
Essay
Similar Content
Neuroscience- Olfactory
olfaction/smell
Biology12th
Cellular Respiration
equation, each part (with notes), glycolysis, krebs cycle, ETC and chemiosmosis, two types of fermentation (lactic acid and alcoholic), ATP
Biology10th
1.1.2 Reliable Witnesses
PLTW Principles of Biomedical Science notes and answers based on activity 1.1.2
HealthRespiratory Body System
The anatomy, important vocab, and common illnesses impacting the respiratory system in the human body.
Biology10th
Cell Energy Notes
diagram and explanation of Cell Energy. Photosynthesis/ Cellular Respiration process and comparison. Explains Fermentation
Biology9th
Cellular Respiration Notes
Google slide presentation on cellular respiration
Biology10th
Most popular content: Cellular Respiration
Most popular content in AP Biology
Most popular content
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
I think it’s very much worth it and you’ll end up using it a lot once you get the hang of it and even after looking at others notes you can still ask your Artificial intelligence buddy the question and ask to simplify it if you still don’t get it!!! In the end I think it’s worth it 😊👍 ⚠️Also DID I MENTION ITS FREEE YOU DON’T HAVE TO PAY FOR ANYTHING AND STILL GET YOUR GRADES IN PERFECTLY❗️❗️⚠️
Thomas R
iOS user
Knowunity is the BEST app I’ve used in a minute. This is not an ai review or anything this is genuinely coming from a 7th grade student (I know 2011 im young) but dude this app is a 10/10 i have maintained a 3.8 gpa and have plenty of time for gaming. I love it and my mom is just happy I got good grades
Brad T
Android user
Not only did it help me find the answer but it also showed me alternative ways to solve it. I was horrible in math and science but now I have an a in both subjects. Thanks for the help🤍🤍
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
I found this app a couple years ago and it has only gotten better since then. I really love it because it can help with written questions and photo questions. Also, it can find study guides that other people have made as well as flashcard sets and practice tests. The free version is also amazing for students who might not be able to afford it. Would 100% recommend
Aubrey
iOS user
Best app if you're in Highschool or Junior high. I have been using this app for 2 school years and it's the best, it's good if you don't have anyone to help you with school work.😋🩷🎀
Marco B
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 app is phenomenal down to the correct info and the various topics you can study! I greatly recommend it for people who struggle with procrastination and those who need homework help. It has been perfectly accurate for world 1 history as far as I’ve seen! Geometry too!
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
I think it’s very much worth it and you’ll end up using it a lot once you get the hang of it and even after looking at others notes you can still ask your Artificial intelligence buddy the question and ask to simplify it if you still don’t get it!!! In the end I think it’s worth it 😊👍 ⚠️Also DID I MENTION ITS FREEE YOU DON’T HAVE TO PAY FOR ANYTHING AND STILL GET YOUR GRADES IN PERFECTLY❗️❗️⚠️
Thomas R
iOS user
Knowunity is the BEST app I’ve used in a minute. This is not an ai review or anything this is genuinely coming from a 7th grade student (I know 2011 im young) but dude this app is a 10/10 i have maintained a 3.8 gpa and have plenty of time for gaming. I love it and my mom is just happy I got good grades
Brad T
Android user
Not only did it help me find the answer but it also showed me alternative ways to solve it. I was horrible in math and science but now I have an a in both subjects. Thanks for the help🤍🤍
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
I found this app a couple years ago and it has only gotten better since then. I really love it because it can help with written questions and photo questions. Also, it can find study guides that other people have made as well as flashcard sets and practice tests. The free version is also amazing for students who might not be able to afford it. Would 100% recommend
Aubrey
iOS user
Best app if you're in Highschool or Junior high. I have been using this app for 2 school years and it's the best, it's good if you don't have anyone to help you with school work.😋🩷🎀
Marco B
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 app is phenomenal down to the correct info and the various topics you can study! I greatly recommend it for people who struggle with procrastination and those who need homework help. It has been perfectly accurate for world 1 history as far as I’ve seen! Geometry too!
Paul T
iOS user