Cellular respiration is the process that cells use to convert...
Biology40 views·Updated Aug 9, 2026·2 pagesUnderstanding Cellular Respiration and Photosynthesis
Meghan M@meghan__
1
of 2
Cellular Respiration Basics and Glycolysis
Cellular respiration happens primarily in mitochondria, the powerhouse organelles with an inner membrane surrounding a matrix. This process uses specific energy carriers—ATP, NADH, and FADH₂—to transfer and store energy throughout the process.
The journey begins with glycolysis, which occurs in the cytoplasm outside the mitochondria. During this first step, 2 ATP molecules are used to split glucose (a 6-carbon molecule) into two 3-carbon pyruvate molecules. This process actually generates 4 ATP and 2 NADH, giving a net gain of 2 ATP molecules.
The Krebs Cycle (also called the citric acid cycle) follows glycolysis and takes place in the mitochondrial matrix. Each pyruvate molecule is broken down into a 2-carbon fragment, releasing CO₂ and creating NADH. The 2-carbon fragment enters the cycle after joining with a molecule called Co-A. Through a series of reactions, more NADH, some ATP, and more CO₂ are produced.
Energy Insight: Every time chemical bonds break during cellular respiration, energy is released. This energy isn't wasted—it's captured in energy-carrying molecules like ATP and NADH that your cells can use later!
2
of 2
Electron Transport Chain and Comparison with Photosynthesis
The Electron Transport Chain (ETC) is where most ATP is generated. High-energy electrons from NADH and FADH₂ travel through protein channels in the inner mitochondrial membrane. This electron movement pumps hydrogen ions across the membrane, creating a concentration gradient. As H+ ions flow back through ATP synthase (like a molecular waterwheel), ATP is produced. The electrons ultimately combine with oxygen and hydrogen ions to form water.
Cellular respiration and photosynthesis are complementary processes. Photosynthesis, occurring in plant chloroplasts, uses water and carbon dioxide to produce glucose and oxygen. Cellular respiration, happening mainly in mitochondria, does the opposite—it breaks down glucose using oxygen to release energy, water, and carbon dioxide.
Both processes use energy carriers, but slightly different ones. Photosynthesis uses ATP/ADP and NADPH/NADP+, while cellular respiration relies on ATP/ADP, NADH/NAD+, and FADH₂/FADH. These carriers shuttle energy between different stages of each process.
Connection Tip: Think of these processes as partners in a global cycle—the waste products of cellular respiration (CO₂ and H₂O) are the raw materials for photosynthesis, while photosynthesis produces the glucose and O₂ needed for cellular respiration!
We thought you’d never ask...
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.
You can download the app in the Google Play Store and in the Apple App Store.
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
Similar Content
Most popular content: Cellular Respiration
1Most popular content in AP Biology
9AP BiologyPhotosynthesis
Photosynthesis-Importance, Formula, Plant Cell.
1,85458
BiologyMitosis vs. Meiosis: Comparison of Divisions, Purpose, and Outcomes
A comparative overview of mitosis and meiosis. It contrasts the purpose, resulting cell types, and division counts for both processes in genetics.
6th3515
BiologyApplying Newtons 3rd Law of Motion
Applying Newtons 3rd Law of Motion
8th1117
BiologyThe Microscope
Describing the Parts of Microscope with Functions
1,23119
BiologyCh 1 - The Human Body; The Orientation
Human Anatomy Introduction: Chapter 1
College442
AP BiologyBody Systems Notes for AP Bio
Notes of the Human Organ Systems with diagrams, functions, main organs, and explanations. Includes 10 human organ systems
52321
ChemistryCarbon Chem - Organic VS Inorganic, Hydrocarbons, Molecular/Structural/Empirical Formula, Functionnal Groups
Review Organic VS Inorganic compounds, learn about Hydrocarbons, Understanding the differences between molecular, structure, and empirical formulas, Prefixes/Suffixes, Functional Groups of carbon.
9th1297
BiologyPlant vs. Animal Cells: Comparing Structures and Functions
Learn to compare and contrast plant and animal cells. Covers major organelles and distinct structures such as the cell wall, central vacuole, and chloroplasts found in plant cells.
6th2101
BiologyAsexual and Sexual Reproduction
Notes describing the effects of asexual and sexual reproduction in biology and organisms
3527
Most popular content
9
AlgebraFAR NOTES- CPM
Compiled by CPM
College2,11847
AP Physics 1Newton's Second Law of Motion
A detailed explanation of Concept of Newton's Second Law of Motion, Examples, Formulas, and Sample Problems with solution.
43614
AlgebraFAR NOTES-HERCULES
LAST MINUTE NOTES BY HERCULES CPA
College1,19818
AlgebraFAR NOTES - KUYA WOWOWIE
Far notes by Kuya Wowowie
College95118
EnglishIntroduction to linguistics
Introduction to linguistics exam revision notes. Structure of language, typologies of language, parts of speech, language families, Chomsky, Hockett, semantic triangle, Prague Linguistic Circle, writing systems, acquisition and learning
1,28153
AlgebraRFBT NOTES- HERCULES
LAST MINUTE NOTES BY HERCULES CPA
College92216
Fun StuffDMV Practice Test 1
First set of Questions from DMV Handbook
1,383131
AlgebraAFAR NOTES- CPM
Compiled by CPM
College1,31817
PhysicsTranslational Motion and Rotational Motion
Applications of Translational and Rotational Motion
11th1791
Students love us — and so will you.
4.6/5App Store
4.7/5Google 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 SiOS 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 KlichAndroid 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.
AnnaiOS user
Biology40 views·Updated Aug 9, 2026·2 pagesUnderstanding Cellular Respiration and Photosynthesis
Meghan M@meghan__
Cellular respiration is the process that cells use to convert glucose into energy. It's like a cellular power plant, breaking down food molecules to produce ATP, which your body uses to fuel nearly everything you do - from thinking to...
1
of 2
Sign up to see the content. It's free!
- Access to all documents
- Improve your grades
- Join milions of students
Cellular Respiration Basics and Glycolysis
Cellular respiration happens primarily in mitochondria, the powerhouse organelles with an inner membrane surrounding a matrix. This process uses specific energy carriers—ATP, NADH, and FADH₂—to transfer and store energy throughout the process.
The journey begins with glycolysis, which occurs in the cytoplasm outside the mitochondria. During this first step, 2 ATP molecules are used to split glucose (a 6-carbon molecule) into two 3-carbon pyruvate molecules. This process actually generates 4 ATP and 2 NADH, giving a net gain of 2 ATP molecules.
The Krebs Cycle (also called the citric acid cycle) follows glycolysis and takes place in the mitochondrial matrix. Each pyruvate molecule is broken down into a 2-carbon fragment, releasing CO₂ and creating NADH. The 2-carbon fragment enters the cycle after joining with a molecule called Co-A. Through a series of reactions, more NADH, some ATP, and more CO₂ are produced.
Energy Insight: Every time chemical bonds break during cellular respiration, energy is released. This energy isn't wasted—it's captured in energy-carrying molecules like ATP and NADH that your cells can use later!
2
of 2Sign up to see the content. It's free!
- Access to all documents
- Improve your grades
- Join milions of students
Electron Transport Chain and Comparison with Photosynthesis
The Electron Transport Chain (ETC) is where most ATP is generated. High-energy electrons from NADH and FADH₂ travel through protein channels in the inner mitochondrial membrane. This electron movement pumps hydrogen ions across the membrane, creating a concentration gradient. As H+ ions flow back through ATP synthase (like a molecular waterwheel), ATP is produced. The electrons ultimately combine with oxygen and hydrogen ions to form water.
Cellular respiration and photosynthesis are complementary processes. Photosynthesis, occurring in plant chloroplasts, uses water and carbon dioxide to produce glucose and oxygen. Cellular respiration, happening mainly in mitochondria, does the opposite—it breaks down glucose using oxygen to release energy, water, and carbon dioxide.
Both processes use energy carriers, but slightly different ones. Photosynthesis uses ATP/ADP and NADPH/NADP+, while cellular respiration relies on ATP/ADP, NADH/NAD+, and FADH₂/FADH. These carriers shuttle energy between different stages of each process.
Connection Tip: Think of these processes as partners in a global cycle—the waste products of cellular respiration (CO₂ and H₂O) are the raw materials for photosynthesis, while photosynthesis produces the glucose and O₂ needed for cellular respiration!
We thought you’d never ask...
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.
You can download the app in the Google Play Store and in the Apple App Store.
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
Similar Content
Most popular content: Cellular Respiration
1Most popular content in AP Biology
9AP BiologyPhotosynthesis
Photosynthesis-Importance, Formula, Plant Cell.
1,85458
BiologyMitosis vs. Meiosis: Comparison of Divisions, Purpose, and Outcomes
A comparative overview of mitosis and meiosis. It contrasts the purpose, resulting cell types, and division counts for both processes in genetics.
6th3515
BiologyApplying Newtons 3rd Law of Motion
Applying Newtons 3rd Law of Motion
8th1117
BiologyThe Microscope
Describing the Parts of Microscope with Functions
1,23119
BiologyCh 1 - The Human Body; The Orientation
Human Anatomy Introduction: Chapter 1
College442
AP BiologyBody Systems Notes for AP Bio
Notes of the Human Organ Systems with diagrams, functions, main organs, and explanations. Includes 10 human organ systems
52321
ChemistryCarbon Chem - Organic VS Inorganic, Hydrocarbons, Molecular/Structural/Empirical Formula, Functionnal Groups
Review Organic VS Inorganic compounds, learn about Hydrocarbons, Understanding the differences between molecular, structure, and empirical formulas, Prefixes/Suffixes, Functional Groups of carbon.
9th1297
BiologyPlant vs. Animal Cells: Comparing Structures and Functions
Learn to compare and contrast plant and animal cells. Covers major organelles and distinct structures such as the cell wall, central vacuole, and chloroplasts found in plant cells.
6th2101
BiologyAsexual and Sexual Reproduction
Notes describing the effects of asexual and sexual reproduction in biology and organisms
3527
Most popular content
9AlgebraFAR NOTES- CPM
Compiled by CPM
College2,11847
AP Physics 1Newton's Second Law of Motion
A detailed explanation of Concept of Newton's Second Law of Motion, Examples, Formulas, and Sample Problems with solution.
43614
AlgebraFAR NOTES-HERCULES
LAST MINUTE NOTES BY HERCULES CPA
College1,19818
AlgebraFAR NOTES - KUYA WOWOWIE
Far notes by Kuya Wowowie
College95118
EnglishIntroduction to linguistics
Introduction to linguistics exam revision notes. Structure of language, typologies of language, parts of speech, language families, Chomsky, Hockett, semantic triangle, Prague Linguistic Circle, writing systems, acquisition and learning
1,28153
AlgebraRFBT NOTES- HERCULES
LAST MINUTE NOTES BY HERCULES CPA
College92216
Fun StuffDMV Practice Test 1
First set of Questions from DMV Handbook
1,383131
AlgebraAFAR NOTES- CPM
Compiled by CPM
College1,31817
PhysicsTranslational Motion and Rotational Motion
Applications of Translational and Rotational Motion
11th1791
Students love us — and so will you.
4.6/5App Store
4.7/5Google 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 SiOS 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 KlichAndroid 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.
AnnaiOS user