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.
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