Lecture 10 - ATP-Synthesis | Plant Metabolism - Botany PDF Download

 Page 1


 ATP Synthesis  
Institute of Life Long Learning, University of Delhi 
 
             
 
 
Lesson Prepared Under MHRD project “ National 
Mission on Education Through ICT” 
 
Discipline: Botany 
Paper: Plant Physiology 
National Coordinator: Prof. S.C. Bhatla 
 
Lesson: ATP Synthesis 
 
Lesson Developer: Dr. Manju A. Lal  
Department of Botany,  
Kirori Mal College, University of Delhi 
 
Lesson Reviewer: Prof. S.C. Bhatla 
Department of Botany, University of Delhi  
 
Language Editor: Namrata Dhaka 
Department/College: Department of Genetics, University of 
Delhi, South Campus 
 
Lesson Editor: Dr Rama Sisodia, Fellow in Botany ILLL 
 
 
 
 
 
 
Page 2


 ATP Synthesis  
Institute of Life Long Learning, University of Delhi 
 
             
 
 
Lesson Prepared Under MHRD project “ National 
Mission on Education Through ICT” 
 
Discipline: Botany 
Paper: Plant Physiology 
National Coordinator: Prof. S.C. Bhatla 
 
Lesson: ATP Synthesis 
 
Lesson Developer: Dr. Manju A. Lal  
Department of Botany,  
Kirori Mal College, University of Delhi 
 
Lesson Reviewer: Prof. S.C. Bhatla 
Department of Botany, University of Delhi  
 
Language Editor: Namrata Dhaka 
Department/College: Department of Genetics, University of 
Delhi, South Campus 
 
Lesson Editor: Dr Rama Sisodia, Fellow in Botany ILLL 
 
 
 
 
 
 
 ATP Synthesis  
 
Institute of Lifelong learning, University of Delhi, South Campus                      2 
 
Chapter: ATP Synthesis 
Table of Contents 
• Introduction 
? Structure of ATP 
? ATP synthesis 
• Coupling of proton transport with ATP synthesis 
• Chemiosmotic hypothesis 
• Oxidative phosphorylation 
? P/O ratio 
? Generation of Reactive Oxygen 
Species (ROS) during oxidative 
phosphorylation 
• Mitochondrial complexes may be 
associated in the form of 
respirosomes 
• Photophosphorylation 
• Comparison of Oxidative phosphorylation 
and Photophosphorylation 
? Evidences for chemiosmotic hypothesis 
• Jagendorf’s experiment 
• EfraimRacker’s experiment 
• Using uncouplers 
? ATP synthase 
• V-type and F-type ATPases 
• Structure of ATP synthase 
? Mechanism of ATP synthesis  
• Binding change mechanism proposed by Paul 
D.Boyer 
• Substrate level phosphorylation 
• Phosphoglycerate kinase 
• Pyruvate kinase 
• Succinly CoA Synthetase 
• Summary 
• References 
• Web links 
 
 
 
 
 
Page 3


 ATP Synthesis  
Institute of Life Long Learning, University of Delhi 
 
             
 
 
Lesson Prepared Under MHRD project “ National 
Mission on Education Through ICT” 
 
Discipline: Botany 
Paper: Plant Physiology 
National Coordinator: Prof. S.C. Bhatla 
 
Lesson: ATP Synthesis 
 
Lesson Developer: Dr. Manju A. Lal  
Department of Botany,  
Kirori Mal College, University of Delhi 
 
Lesson Reviewer: Prof. S.C. Bhatla 
Department of Botany, University of Delhi  
 
Language Editor: Namrata Dhaka 
Department/College: Department of Genetics, University of 
Delhi, South Campus 
 
Lesson Editor: Dr Rama Sisodia, Fellow in Botany ILLL 
 
 
 
 
 
 
 ATP Synthesis  
 
Institute of Lifelong learning, University of Delhi, South Campus                      2 
 
Chapter: ATP Synthesis 
Table of Contents 
• Introduction 
? Structure of ATP 
? ATP synthesis 
• Coupling of proton transport with ATP synthesis 
• Chemiosmotic hypothesis 
• Oxidative phosphorylation 
? P/O ratio 
? Generation of Reactive Oxygen 
Species (ROS) during oxidative 
phosphorylation 
• Mitochondrial complexes may be 
associated in the form of 
respirosomes 
• Photophosphorylation 
• Comparison of Oxidative phosphorylation 
and Photophosphorylation 
? Evidences for chemiosmotic hypothesis 
• Jagendorf’s experiment 
• EfraimRacker’s experiment 
• Using uncouplers 
? ATP synthase 
• V-type and F-type ATPases 
• Structure of ATP synthase 
? Mechanism of ATP synthesis  
• Binding change mechanism proposed by Paul 
D.Boyer 
• Substrate level phosphorylation 
• Phosphoglycerate kinase 
• Pyruvate kinase 
• Succinly CoA Synthetase 
• Summary 
• References 
• Web links 
 
 
 
 
 
 ATP Synthesis  
 
Institute of Lifelong learning, University of Delhi, South Campus                      3 
 
Learning outcomes 
 
The objectives of this lesson are to learn about the following: 
? Chemiosmotic mechanism for ATP synthesis. 
? Evidences that support chemiosmotic mechanism for ATP synthesis. 
? Structure of ATP synthase. 
? Mechanism of coupling of proton transport through ATP synthase with ATP 
synthesis. 
? Substrate-level phosphorylation. 
 
Introduction 
In the previous lessons you have studied how reduced coenzymes, NADH and 
FADH
2 
are produced during the glucose breakdown through glycolysis and TCA 
cycle. You have also studied oxidation of NADH and FADH2 through electron 
transport chain, which is localized in the inner mitochondrial membrane.  
 
 
Figure: Structure of mitochondria.  
Source: http://en.wikibooks.org/wiki/Cell_Biology/Organelles/Mitochondria (cc) 
 
In this lesson you will study how ATP is synthesized. ATP is called the molecular 
energy currency of the cell. It means that the exchange of energy occurs in the 
form of ATP molecule. ATP synthesis is energy- consuming reaction (endergonic) 
and is coupled to energy releasing reaction (exergonic). The energy of the 
exergonic reaction is stored in the form of ATP molecule. Whenever energy is 
required by the cell for various functions for example, intracellular transport, 
Page 4


 ATP Synthesis  
Institute of Life Long Learning, University of Delhi 
 
             
 
 
Lesson Prepared Under MHRD project “ National 
Mission on Education Through ICT” 
 
Discipline: Botany 
Paper: Plant Physiology 
National Coordinator: Prof. S.C. Bhatla 
 
Lesson: ATP Synthesis 
 
Lesson Developer: Dr. Manju A. Lal  
Department of Botany,  
Kirori Mal College, University of Delhi 
 
Lesson Reviewer: Prof. S.C. Bhatla 
Department of Botany, University of Delhi  
 
Language Editor: Namrata Dhaka 
Department/College: Department of Genetics, University of 
Delhi, South Campus 
 
Lesson Editor: Dr Rama Sisodia, Fellow in Botany ILLL 
 
 
 
 
 
 
 ATP Synthesis  
 
Institute of Lifelong learning, University of Delhi, South Campus                      2 
 
Chapter: ATP Synthesis 
Table of Contents 
• Introduction 
? Structure of ATP 
? ATP synthesis 
• Coupling of proton transport with ATP synthesis 
• Chemiosmotic hypothesis 
• Oxidative phosphorylation 
? P/O ratio 
? Generation of Reactive Oxygen 
Species (ROS) during oxidative 
phosphorylation 
• Mitochondrial complexes may be 
associated in the form of 
respirosomes 
• Photophosphorylation 
• Comparison of Oxidative phosphorylation 
and Photophosphorylation 
? Evidences for chemiosmotic hypothesis 
• Jagendorf’s experiment 
• EfraimRacker’s experiment 
• Using uncouplers 
? ATP synthase 
• V-type and F-type ATPases 
• Structure of ATP synthase 
? Mechanism of ATP synthesis  
• Binding change mechanism proposed by Paul 
D.Boyer 
• Substrate level phosphorylation 
• Phosphoglycerate kinase 
• Pyruvate kinase 
• Succinly CoA Synthetase 
• Summary 
• References 
• Web links 
 
 
 
 
 
 ATP Synthesis  
 
Institute of Lifelong learning, University of Delhi, South Campus                      3 
 
Learning outcomes 
 
The objectives of this lesson are to learn about the following: 
? Chemiosmotic mechanism for ATP synthesis. 
? Evidences that support chemiosmotic mechanism for ATP synthesis. 
? Structure of ATP synthase. 
? Mechanism of coupling of proton transport through ATP synthase with ATP 
synthesis. 
? Substrate-level phosphorylation. 
 
Introduction 
In the previous lessons you have studied how reduced coenzymes, NADH and 
FADH
2 
are produced during the glucose breakdown through glycolysis and TCA 
cycle. You have also studied oxidation of NADH and FADH2 through electron 
transport chain, which is localized in the inner mitochondrial membrane.  
 
 
Figure: Structure of mitochondria.  
Source: http://en.wikibooks.org/wiki/Cell_Biology/Organelles/Mitochondria (cc) 
 
In this lesson you will study how ATP is synthesized. ATP is called the molecular 
energy currency of the cell. It means that the exchange of energy occurs in the 
form of ATP molecule. ATP synthesis is energy- consuming reaction (endergonic) 
and is coupled to energy releasing reaction (exergonic). The energy of the 
exergonic reaction is stored in the form of ATP molecule. Whenever energy is 
required by the cell for various functions for example, intracellular transport, 
 ATP Synthesis  
 
Institute of Lifelong learning, University of Delhi, South Campus                      4 
 
transport of ions/molecules into or out of the cell against the concentration 
gradient, transduction of the signals across cell membranes or for carrying out 
various chemical reactions that require energy, the energy used is in the form of 
ATP. What we understand is that the energy exchange in between various cell 
reactions occurs in the form of ATP. In all the living organisms, whether it the 
simplest types such as prokaryotes, or the higher organisms, there is universal 
occurrence of this molecule. What makes this molecule so important that it is 
universally present? The scientists have tried to understand the structure of the 
ATP molecule and also the mechanism of its synthesis. 
Besides the role of ATP as the molecular energy currency of the cell, it can be 
converted to cyclic AMP by adenylate cyclase, which plays an important role as 
secondary messenger in signal transduction in eukaryotic cells. 
 
ATP was first discovered in 1929 by German chemist Karl Lohmann, Fieske and 
Y.Subbarow of Harverd Medical School. Fritz Albert Lipman in 1941, for the first 
time demonstrated ATP to be the universal energy carrier of the cell. He shared 
Nobel Prize with Hans Krebs in 1953. Lipman used the term ‘high energy bonds’ 
and symbols ~P for compounds having a high phosphate group transfer potential. 
Its structure was deciphered by the English chemist Alexander Todd and he was 
able to synthesize ATP in 1948. Todd won the Noble Prize in 1957. 
 
Page 5


 ATP Synthesis  
Institute of Life Long Learning, University of Delhi 
 
             
 
 
Lesson Prepared Under MHRD project “ National 
Mission on Education Through ICT” 
 
Discipline: Botany 
Paper: Plant Physiology 
National Coordinator: Prof. S.C. Bhatla 
 
Lesson: ATP Synthesis 
 
Lesson Developer: Dr. Manju A. Lal  
Department of Botany,  
Kirori Mal College, University of Delhi 
 
Lesson Reviewer: Prof. S.C. Bhatla 
Department of Botany, University of Delhi  
 
Language Editor: Namrata Dhaka 
Department/College: Department of Genetics, University of 
Delhi, South Campus 
 
Lesson Editor: Dr Rama Sisodia, Fellow in Botany ILLL 
 
 
 
 
 
 
 ATP Synthesis  
 
Institute of Lifelong learning, University of Delhi, South Campus                      2 
 
Chapter: ATP Synthesis 
Table of Contents 
• Introduction 
? Structure of ATP 
? ATP synthesis 
• Coupling of proton transport with ATP synthesis 
• Chemiosmotic hypothesis 
• Oxidative phosphorylation 
? P/O ratio 
? Generation of Reactive Oxygen 
Species (ROS) during oxidative 
phosphorylation 
• Mitochondrial complexes may be 
associated in the form of 
respirosomes 
• Photophosphorylation 
• Comparison of Oxidative phosphorylation 
and Photophosphorylation 
? Evidences for chemiosmotic hypothesis 
• Jagendorf’s experiment 
• EfraimRacker’s experiment 
• Using uncouplers 
? ATP synthase 
• V-type and F-type ATPases 
• Structure of ATP synthase 
? Mechanism of ATP synthesis  
• Binding change mechanism proposed by Paul 
D.Boyer 
• Substrate level phosphorylation 
• Phosphoglycerate kinase 
• Pyruvate kinase 
• Succinly CoA Synthetase 
• Summary 
• References 
• Web links 
 
 
 
 
 
 ATP Synthesis  
 
Institute of Lifelong learning, University of Delhi, South Campus                      3 
 
Learning outcomes 
 
The objectives of this lesson are to learn about the following: 
? Chemiosmotic mechanism for ATP synthesis. 
? Evidences that support chemiosmotic mechanism for ATP synthesis. 
? Structure of ATP synthase. 
? Mechanism of coupling of proton transport through ATP synthase with ATP 
synthesis. 
? Substrate-level phosphorylation. 
 
Introduction 
In the previous lessons you have studied how reduced coenzymes, NADH and 
FADH
2 
are produced during the glucose breakdown through glycolysis and TCA 
cycle. You have also studied oxidation of NADH and FADH2 through electron 
transport chain, which is localized in the inner mitochondrial membrane.  
 
 
Figure: Structure of mitochondria.  
Source: http://en.wikibooks.org/wiki/Cell_Biology/Organelles/Mitochondria (cc) 
 
In this lesson you will study how ATP is synthesized. ATP is called the molecular 
energy currency of the cell. It means that the exchange of energy occurs in the 
form of ATP molecule. ATP synthesis is energy- consuming reaction (endergonic) 
and is coupled to energy releasing reaction (exergonic). The energy of the 
exergonic reaction is stored in the form of ATP molecule. Whenever energy is 
required by the cell for various functions for example, intracellular transport, 
 ATP Synthesis  
 
Institute of Lifelong learning, University of Delhi, South Campus                      4 
 
transport of ions/molecules into or out of the cell against the concentration 
gradient, transduction of the signals across cell membranes or for carrying out 
various chemical reactions that require energy, the energy used is in the form of 
ATP. What we understand is that the energy exchange in between various cell 
reactions occurs in the form of ATP. In all the living organisms, whether it the 
simplest types such as prokaryotes, or the higher organisms, there is universal 
occurrence of this molecule. What makes this molecule so important that it is 
universally present? The scientists have tried to understand the structure of the 
ATP molecule and also the mechanism of its synthesis. 
Besides the role of ATP as the molecular energy currency of the cell, it can be 
converted to cyclic AMP by adenylate cyclase, which plays an important role as 
secondary messenger in signal transduction in eukaryotic cells. 
 
ATP was first discovered in 1929 by German chemist Karl Lohmann, Fieske and 
Y.Subbarow of Harverd Medical School. Fritz Albert Lipman in 1941, for the first 
time demonstrated ATP to be the universal energy carrier of the cell. He shared 
Nobel Prize with Hans Krebs in 1953. Lipman used the term ‘high energy bonds’ 
and symbols ~P for compounds having a high phosphate group transfer potential. 
Its structure was deciphered by the English chemist Alexander Todd and he was 
able to synthesize ATP in 1948. Todd won the Noble Prize in 1957. 
 
 ATP Synthesis  
 
Institute of Lifelong learning, University of Delhi, South Campus                      5 
 
Figure: ATP as energy currency of the cell. 
Source: http://cnx.org/contents/14fb4ad7-39a1-4eee-ab6e-
3ef2482e3e22@6.17:163/Anatomy_&_Physiology (cc) 
 
Structure of ATP 
ATP is Adenosine Triphosphate. As the name indicates it is a nucleoside 
(Adenosine) to which three phosphate groups are attached. 
 
Figure: Structure of ATP molecule 
Source:http://commons.wikimedia.org/wiki/File:230_Structure_of_Adenosine_Tri
phosphate_%28ATP%29-01.jpg (cc) 
 
Why is ATP a high energy molecule? 
There are three reasons for ATP to be selected as high energy molecule by the 
nature: 
1. There is electrostatic repulsion between the four negatively charged oxygen and 
positively charged phosphorus, which is stabilized in the products (ADP + Pi) 
formed, after breaking of the bonds. 
2. Products of hydrolysis are stabilized by ionization and resonance. With the 
breaking of high energy bonds there is increased stability due to resonance of the 
product structures. 
3. With the hydrolysis of ATP there is an increase in entropy, because the products 
are more stable than the ATP molecule itself.