1) Oxidative phosphorylation uses electron transport chain complexes in the mitochondrial inner membrane to generate ATP from ADP and inorganic phosphate. As electrons are passed through Complexes I-IV, protons are pumped from the matrix to the intermembrane space, building an electrochemical gradient.
2) Protons flow back through ATP synthase, driving the phosphorylation of ADP to ATP in the matrix. The electron carriers, including ubiquinone and cytochrome c, shuttle electrons and protons between the complexes.
3) Oxygen is the final electron acceptor, being reduced to water along with protons in Complex IV. This chemiosmotic mechanism couples electron transport to ATP synthesis via the proton gradient across the inner mitochondrial membrane
Protein Structure, Post Translational Modifications and Protein FoldingSuresh Antre
Post-translational modifications (PTMs) are covalent processing events that change the properties of a protein by proteolytic cleavage or by addition of a modifying group to one or more amino acids.
Protein post-translational modification (PTM) plays an essential role in various cellular processes that modulates the physical and chemical properties, folding, conformation, stability and activity of proteins, thereby modifying the functions of proteins
Chaperones are a functionally related group of proteins that assist the covalent folding or unfolding and the assembly or disassembly of other macromolecular structures.
This is based on protein-ligand interaction physical method, which gives us knowledge about how our body protein interacts with other molecule and protein function.
Electron Transport Chain and oxidative phosphorylation @meetpadhiyarmeetpadhiyar88
A story of electron transport to the ATP synthase complex by 4 complexes and oxidative phosphorylation.
Present at College of basic science and Humanities, Dantiwada.
Biological oxidation (part - III) Oxidative PhosphorylationAshok Katta
Biological oxidation (part - III) Oxidative Phosphorylation
- Mechanism of Oxidative Phosphorylation
-- Chemiosmotic theory
-P:O Ratio
Substrate Level Phosphorylation
Shuttle Systems for Oxidation of Extramitochondrial NADH
Glucose transporters are a wide group of membrane proteins that facilitate the transport of glucose across the plasma membrane, a process known as facilitated diffusion. Because glucose is a vital source of energy for all life, these transporters are present in all phyla.
Protein Structure, Post Translational Modifications and Protein FoldingSuresh Antre
Post-translational modifications (PTMs) are covalent processing events that change the properties of a protein by proteolytic cleavage or by addition of a modifying group to one or more amino acids.
Protein post-translational modification (PTM) plays an essential role in various cellular processes that modulates the physical and chemical properties, folding, conformation, stability and activity of proteins, thereby modifying the functions of proteins
Chaperones are a functionally related group of proteins that assist the covalent folding or unfolding and the assembly or disassembly of other macromolecular structures.
This is based on protein-ligand interaction physical method, which gives us knowledge about how our body protein interacts with other molecule and protein function.
Electron Transport Chain and oxidative phosphorylation @meetpadhiyarmeetpadhiyar88
A story of electron transport to the ATP synthase complex by 4 complexes and oxidative phosphorylation.
Present at College of basic science and Humanities, Dantiwada.
Biological oxidation (part - III) Oxidative PhosphorylationAshok Katta
Biological oxidation (part - III) Oxidative Phosphorylation
- Mechanism of Oxidative Phosphorylation
-- Chemiosmotic theory
-P:O Ratio
Substrate Level Phosphorylation
Shuttle Systems for Oxidation of Extramitochondrial NADH
Glucose transporters are a wide group of membrane proteins that facilitate the transport of glucose across the plasma membrane, a process known as facilitated diffusion. Because glucose is a vital source of energy for all life, these transporters are present in all phyla.
The electron transport chain is comprised of a series of enzymatic reactions within the inner membrane of the mitochondria, which are cell organelles that release and store energy for all physiological needs.
As electrons are passed through the chain by a series of oxidation-reduction reactions, energy is released, creating a gradient of hydrogen ions, or protons, across the membrane. The proton gradient provides energy to make ATP, which is used in oxidative phosphorylation.
Describe the major components of the electron transport chain. How w.pdfduttakajal70
Describe the major components of the electron transport chain. How would the following
conditions affect ATP production by the electron transport chain? (7 marks)
Abundance of NADH and O2
Cyanide added
Lack of O2
Solution
There are five major components in electron system. They are:
Complex I:
It is a large, multisubunit complex with about 40 polypeptide chains passes electron from NADH
to CoQ. It contains one molecule of FMN and 6-7 Fe-S clusters that participate in electron
transport process. During transport of each pair of electrons from NADH to coenzyme Q,
complex I pumps 4 protons across the inner mitochondrial membrane.
Complex II:
Succinate dehrogenase, an inner mitochondrial membrane bound enzyme is an integral
component of the succinate-CoQ reductase complex. It converts succinate to fumarate during
krebs cycle. The two electrons released in the conversion of succinate to fumarate are transferred
first to FAD, then to an Fe-S centre, and finally to CoQ. Thus, CoQ draws electrons into the
respiratory chain, not only from NADH but also from succinate. No protons are translocated
across the membrane by this complex.
Complex III:
Complex I and complex II donates two electrons to the complex III and regenerates oxidized
CoQ. Concomitantly, it releases two protons picked up on the cytosolic face into the
intermembrane space generating proton gradient. Within complex III, the released electrons are
transferred to an Fe-S centre and then to 2b-type cytochromes or cytochrome c. finally, the two
electrons are transferred to 2 molecules of the oxidized form of cytochrome c. 2 additional
protons are translocated from the mitochondrial matrix across the inner mitochondrial membrane
for each pair of electrons transferred.
Complex IV:
Cytochrome c transports electrons, one at a time, to the complex IV. Within this complex,
electrons are transferred, first to a pair of copper ions, then to cytochrome a, next to a complex of
another copper ion and cyt a3 and finally to O2, the ultimate electron acceptor, yielding H2O.
ATP synthase:
The use of proton motive force for synthesis is catalyzed by ATP synthase. The multi protein
ATP synthase for F0-F1 complex or complex V catalyzes ATP synthesis as protons flow back
through the inner membrane down the electrochemical proton gradient.
2. Abundance of NADH and O2:
ETC occurs more to produce more ATP.
Cyanide added:
Cyanide binds with cytochrome oxidase complex and inhibits the terminal transfer of electrons
to oxygen. Cyanide react with the oxidized form of cytochrome.
Lack of O2:
ETC will not take place in the absence of oxygen..
Electron Transport Chain and oxidative phosphorylationusmanzafar66
substrate level phosphorylation and chemiosmosis
in Eukaryotes and in prokaryotes
in plant and animal
uncoupler oxidative phosphorylation
fat and protein ATP calculation
B.Sc Micro II Microbial physiology Unit 2 Bacterial RespirationRai University
Respiration is the energy source to all living organism. Bacterial ETS system generates energy for bacteria in form of ATP using oxidative phosphorylation.
How to Build a Module in Odoo 17 Using the Scaffold MethodCeline George
Odoo provides an option for creating a module by using a single line command. By using this command the user can make a whole structure of a module. It is very easy for a beginner to make a module. There is no need to make each file manually. This slide will show how to create a module using the scaffold method.
This presentation includes basic of PCOS their pathology and treatment and also Ayurveda correlation of PCOS and Ayurvedic line of treatment mentioned in classics.
Executive Directors Chat Leveraging AI for Diversity, Equity, and InclusionTechSoup
Let’s explore the intersection of technology and equity in the final session of our DEI series. Discover how AI tools, like ChatGPT, can be used to support and enhance your nonprofit's DEI initiatives. Participants will gain insights into practical AI applications and get tips for leveraging technology to advance their DEI goals.
A Strategic Approach: GenAI in EducationPeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
Delivering Micro-Credentials in Technical and Vocational Education and TrainingAG2 Design
Explore how micro-credentials are transforming Technical and Vocational Education and Training (TVET) with this comprehensive slide deck. Discover what micro-credentials are, their importance in TVET, the advantages they offer, and the insights from industry experts. Additionally, learn about the top software applications available for creating and managing micro-credentials. This presentation also includes valuable resources and a discussion on the future of these specialised certifications.
For more detailed information on delivering micro-credentials in TVET, visit this https://tvettrainer.com/delivering-micro-credentials-in-tvet/
Thinking of getting a dog? Be aware that breeds like Pit Bulls, Rottweilers, and German Shepherds can be loyal and dangerous. Proper training and socialization are crucial to preventing aggressive behaviors. Ensure safety by understanding their needs and always supervising interactions. Stay safe, and enjoy your furry friends!
1. 1
Oxidative phosphorylation and
photophosphorylation
keystone concepts:
• Oxidative phosphorylation is the enzymatic synthesis of ATP coupled to
the transfer of electrons (e-) to oxygen
• The mitochondrial respiratory chain is an ordered array of electron
carriers arranged in complexes
• Complex I is a transmembrane protein complex of the inner
mitochondrial membrane that accepts e- from NADH
• Complex II (succinate dehydrogenase) transfers e- from succinate to FAD
and then to the Fe-S centers and then to ubiquinone (Coenzyme Q)
• Complex III transfers e- from ubiquinone (QH2) to cytochrome c
• Complex IV receives e- from cytochrome c and passes them to the final
e- acceptor (O2)
• The chemiosmotic model explains how the proton gradient generated by
e- flow drives ATP synthesis
2. Impermeable to
ions and most
other compounds
In inner
membrane
mitochondrion
the mitochondrion contained the enzymes responsible for
electron transport and oxidative phosphorylation
3. 3
anatomy of a
mitochondrion
Where is ATP synthesized?
Where are the citric acid cycle and
β-oxidation pathways?
Which membranes are permeable?
5. 5
Where do the electrons come from?
Where do they go?
• All the dehydrogenase reactions in the citric acid cycle, b-
oxidation and amino acid oxidation and glycolysis
– Hydride ion transfers + hydrogen atom transfers
• Electron carriers in addition to NAD and flavoproteins:
1. Ubiquinone (aka. Coenzyme Q) - a fat soluble mobile protein
2. Cytochromes – iron containing e- transfer proteins (in heme)
3. Iron sulfur proteins – (not in heme) but where iron is directly
associated with inorganic sulfur or the sulfur on cysteine
residues
6. NAD+, flavins and Q carry electrons and H+
Cytochromes and non-heme iron proteins carry only
electrons
NAD+, FAD undergoes only a 2 e- reaction;
cytochromes undergo only 1e- reactions
FMN, Q undergoes 1e- and 2 e- reaction
Electron carriers
7. Ubiquinone
• Coenzyme Q (CoQ, or Q) is lipid-soluble. It
dissolves in the hydrocarbon core of a
membrane.
• the only electron carrier not bound to a
protein.
• it can accept/donate 1 or 2 e-. Q can mediate
e- transfer between 2 e- and 1 e- carriers
9. Cytochromes are electron carriers containing
hemes . Hemes in 3 classes of cytochrome (a, b, c)
differ in substituents on the porphyrin ring.
Some cytochromes(b,c1,a,a3) are part of large
integral membrane protein complexes (such as
complex III).
Cytochrome c is a small, water-soluble protein.
Cytochromes
11. The heme iron can undergo 1 e- transition between
ferric and ferrous states: Fe3+ + e- Fe2+
Copper ions besides two heme A groups (a and a3)
act as electron carriers in CuB, accepting electrons
from heme a
Cu2++e- Cu+
Heme is a prosthetic group of cytochromes.
Heme contains an iron atom in a porphyrin ring system.
13. Iron-sulfur centers (Fe-S) are prosthetic groups containing 1-4 iron
atoms
Iron-sulfur centers transfer only one electron, even if they contain
two or more iron atoms.
E.g., a 4-Fe center might cycle between redox states:
3Fe+++ + Fe++ + 1 e- 2Fe+++ + 2Fe++
Iron-sulfur Centers
16. Electron Transport chain
• The electron transport chain in the inner
mitochondrial membrane can be isolated in
four proteins complexes(I, II, III, IV).
• A lipid soluble coenzyme (Q) and a water
soluble protein (cyt c) shuttle between protein
complexes
• Electrons transfer through the chain - from
complexes I to complex IV
17. NAD+
FMN
FeS
ubiquinoneFAD FeS
Cyt b
FeS Cyt c1 Cyt c Cyt a Cyt a3
1/2 O2
ubiquinone
I
II
III IV
Mitochondrial Complexes
NADH Dehydrogenase
Succinate
dehydrogenase
CoQ-cyt c Reductase
Cytochrome Oxidase
19. Support for this order of events
1. Energetically favorable. electrons pass from lower
to higher standard reduction potentials
2. Spectra: the absorption spectrum for the reduced
carrier differs from that of its oxidized form.
carriers closer to oxygen are more oxidized.
3. Specific inhibitors. Those before the blocked step
should be reduced and those after be oxidized.
1. Assay of individual complexes: NADH can reduce complex I
but not the other complexes.
20. H+ Transport
Complex I, III, IV drive H+ transport from
matrix to the cytosol when e- flow through,
which creates proton gradient
Creates an electrochemical potential across
the inner membrane
21. 1.Electrons are transported along the inner
mitochondrial membrane, through a series of
electron carriers
2.Protons (indicated by + charge) are translocated
across the membrane, from the matrix to the
intermembrane space
3.Oxygen is the terminal electron acceptor,
combining with electrons and H+ ions to produce
water
4. As NADH delivers more H+ and electrons into
the ETS, the proton gradient increases, with H+
building up outside the inner mitochondrial
membrane
22. Complex I: NADH dehydrogenase
• NADH binds complex I & passes 2 electrons to
a flavin momonucleotide (FMN) prosthetic
group.
• The FMN is reduced to FMNH2. Each electron
is transferred with a proton.
• The electrons are then passed to iron-sulphur
proteins (FeS) in complex I (this is non-heme
iron). The electron is accepted by Fe3+ which is
reduced to Fe2+
23.
24. Complex I
• Two electrons from the reduced FeS proteins
are then passed to CoQ along with 2 protons.
• The CoQ is thus reduced to CoQH2
(ubiquinol) while the FeS proteins are
oxidized back to Fe3+ state.
25. CoQ is small and lipid soluble so it is mobile in the mitochondrial
membrane. It diffuses easily and shuttles the electrons to
complex III
27. Complex II: Succinate dehydrogenase
• Complex II actually contains the enzyme
succinate dehydrogenase which catalyses the
reduction of succinate to fumarate (reaction of
the citric acid cycle).
• FAD oxidizes succinate to fumarate (FAD
becoming reduced to FADH2 as it picks up 2
electrons and 2 protons).
• FADH2 is oxidized back to FAD by passing the
electrons on to FeS proteins in complex II. The
electrons are then passed to CoQ and are passed
on to complex III
29. Complex III: cytochrome reductase
• Complex III contains cytochrome b, cytochrome
c1 and FeS proteins.
• Like FeS proteins, cytochromes contain bound Fe
atoms in heme.
• The iron atoms alternate between +3 and +2
oxidation states as they pass on the electrons.
• CoQH2 passes 2 electrons to cyt b causing the
Fe3+ to be reduced to Fe2+.
• The electrons are passed to the FeS protein and
then to cyt c1.
30.
31. 31
Complex III: QH2 to cytochrome c
-not a direct
proton path
across membrane
32. Cytochrome C
• Cyt c is another small mobile protein.
• It accepts electrons from complex III (Fe3+ is
reduced to Fe2+) and shuttles them to the last
electron transport protein in the chain
(complex IV).
33.
34. Complex IV: cytochrome oxidase
• Complex IV contains cytochrome a and
cytochrome a3 (both use Fe and Cu atoms to
handle the electrons).
• Four cytochrome c molecules pass on 4
electrons to complex IV.
• These are eventually transferred with 4 H+ to
O2 to form 2 water molecules.
36. Cytochrome C oxidase combines electrons with oxygen and 4H+
to form 2 water
Oxygen = final electron acceptor
37. Paths of H+ and e- transfer in
cytochrome c oxidase
Blue- chemical reaction of O2
reduction to water
coupled to
Red- translocation of four
protons
e- flow from red cyt c in inner
mem space CuA center
heme a3-CuB center reduce O2
H+ from matrix:
-shuttled to heme a3-CuB site
and consumed in production of
H2O
Or
-transloacted across mem
Intermembrane
space
Matrix
38. 38
summary of e- flow from complex I-IV
• Transfer of e- from NADH, energy is conserved in the
proton gradient (called the proton motive force)
• Energy is used to pump protons across the membrane,
which can then be used for work (ATP synthesis)
39. The proton pumps are Complexes I,
III and IV.
Protons return thru ATP synthase
40. Chemiosmotic model
• Electron transport linked to ATP synthesis
• Protons “trapped” in intermembrane space form
electrochemical gradient
• Protons flow down gradient through ATP synthase complex
– phosphorylates ADP and Pi to form ATP
41. -- The protons have a thermodynamic
tendency to return to the matrix =
Proton-motive force
The proton move back into the matrix
through the
FoF1ATP
synthase
driving
ATP synthesis.
42. ATP Synthase
• aka F1F2- ATPase
• Couples the flow of E- across the inner
mitochondrial membrane to synthesis of
ATP (reverse reaction also possible)
• 18 subunits (mammals) “molecular
machine”
43. 43
mitochondrial ATP synthase complex: FoF1
ATP synthase complex
• Couples the flow of
e- across the inner
mitochondrial
membrane to
synthesize of ATP
(reverse reaction
also possible)
• 18 subunits
(mammals)
44. H+
catalytic
head
rod
rotor
H+
H+
H+
H+ H+
H+H+
H+
FoF1 ATP synthase
ATP
ADP P+
• Enzyme channel in
mitochondrial membrane
– permeable to H+
– H+ flow down
concentration gradient
• flow like water over
water wheel
• flowing H+ cause
change in shape of
ATP synthase enzyme
• powers binding of
Pi to ADP
ADP + Pi ATP
45. FoF1 ATP synthase
-- ATP synthesized on matrix side.
-- electron transport complexes
and FoF1 ATP synthase arranged
on the inner membrane of the
mitochondrion facing in and lining
the membranes.
46. The return of protons “downhill”
through Fo rotates Fo
relative to F1,
driving ATP
synthesis.
-Note: Subunit
rotates
through F1.
-Catalytic sites
are located in
the α/β interfaces
47. 47
Where do the substrates come from?
Where do the products go?
48. Mitochondrial ATP transport
• Charge difference between ATP4-
and ADP3- provides driving force
for translocation
– ATP moves from more negative
matrix to more positive
intermembrane space
– ADP moves in opposite
direction
– Reduces charge gradient across
inner membrane by 1
49. Respiratory Control
-- Most mitochondria are said to be
tightly coupled.
That is there is no electron flow
without phosphorylation and no
phosphorylation without
electron flow.
-- Substrate ADP, Pi and O2
are all necessary for
oxidative phosphorylation.
50. For example, in the absence of ADP
or O2 electron flow stops, reduced
substrate is not consumed and no
ATP is made = acceptor control.
Under certain conditions, coupling
can be lost.
51. -- Brown adipose
(fat) cells
contain natural
uncouplers to
warm animals -
cold adaptation
and hibernation.
53. NADH shuttles
• NADH produced in cytosol during glycolysis
• Mitochondrial membranes impermeable to
NADH
– Reducing equivalents shuttled into
mitochondria to ETC
• Two shuttles operate:
– Glycerol phosphate shuttle
– Malate-aspartate shuttle
54. Glycerol phosphate shuttle
• Operates to minor extent
in variety of tissues, but
very important in Skeletal
muscle and brain
• Transfers reducing
equivalents held by
cytosolic NADH to FAD in
ETC
55. Malate-aspartate shuttle
• Dominant shuttle in liver, kidney and heart
• Transfers reducing equivalents held by cytosolic NADH to NAD in ETC