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VIETNAM NATIONAL UNIVERSITY - HO CHI MINH CITY  
INTERNATIONAL UNIVERSITY                 
DYSREGULATION OF OXIDATIVE  
PHOSPHORYLATION IN HUMAN DISEASES         GROUP 8:  
Lâm Gia Nghi BTBCIU18097 Phạm  Mỹ Nhàn BTBCIU19054  Đào Thanh Trúc BTBCIU18096    
INSTRUCTOR: Vũ Thanh Ngọc                            May 2023     ACKNOWLEDGEMENT 
This literature review has been completed successfully with much support. We would like 
to express our sincere appreciation to our instructor, Vũ Thanh Ngọc for assigning us the 
topic “Dysregulation of Oxidative phosphorylation in human diseases, which help us 
learn more new things and experience in research and academic writing. Her enthusiasm 
and immense knowledge have inspired us to accumulate more knowledge and follow the 
biochemistry field. Furthermore, we would like to make a special thanks to our family for 
their unconditional support, nursing, and understanding. No written word can adequately 
express our appreciation to all the people. We are delighted to get acquainted with you.              TABLE OF CONTENTS  
ABSTRACT ...................................................................................................................... 1 
1. INTRODUCTION ....................................................................................................... 1 
1.1. Overview of mitochondria ........................................................................... 1 
1.2. Overview of oxidative phosphorylation ..................................................... 2 
1.2.1. Definition of oxidative phosphorylation ..................................................... 2 
1.2.2. Synthesis of ATP ......................................................................................... 4 
2. REGULATION OF OXIDATIVE PHOSPHORYLATION .................................... 5 
3. DYSREGULATION OF THE PATHWAY IN HUMAN DISEASES ..................... 8 
3.1. Oxidative phosphorylation in the human body .......................................... 8     
3.1.1. The oxidative phosphorylation (OXPHOS) pathway and its role in cells 
and the human body ............................................................................................... 8 
3.1.2. The interest of scientists in studying the abnormalities and dysregulation 
of the OXPHOS pathway in diseases .................................................................... 8 
3.2. Methods to detect abnormalities and dysregulation of the OXPHOS 
pathway ................................................................................................................. 9 
3.2.1. The method of analyzing the functional domain of the OXPHOS 
pathway .................................................................................................................. 9 
3.2.2. The method of analyzing genes ................................................................. 10 
3.2.3. The method of analyzing proteins ............................................................. 11 
3.2.4. The method of evaluating cellular functions and energy .......................... 12 
4. CONCLUSION .......................................................................................................... 13 
REFERENCES ............................................................................................................... 15    LIST OF FIGURES 
Figure 1. Animation of mitochondria structure (Margarida Azevedo, 2015) .................. 2 
Figure 2. The electron transport chain in the inner membrane of mitochondria (John P. 
Rafferty, 2017) ..................................................................................................................  3 
Figure 3. ATP synthase pumps protons back to generate ATP (Klaus Hoffmeier, 2020) 4 
Figure 4. The two components of the electrochemical proton gradient (Alberts et al., 
2002). ................................................................................................................................  7    LIST OF ABBREVIATIONS  ADP  Adenosine diphosphate  ATP  Adenosine Triphosphate  ETC  Electron transport chain  FADH2  Flavin adenine dinucleotide  FoF1-ATPase  proton-pumping ATP synthase  NADH 
Nicotinamide adenine dinucleotide  OXPHOS  Oxidative phosphorylation        PFK-1  phosphofructokinase-1    Pi  Free phosphate  SNPs  Nucleotide polymorphisms  TCA  Tricarboxylic acid      lOMoARcPSD|47231818
Dysregulation of Oxidative phosphorylation in human diseases  
Lâm Gia Nghi a, Phạm Mỹ Nhàn a, Đào Thanh Trúc a a School of Biotechnology, 
International University – Vietnam National University in HCMC    ABSTRACT 
Oxidative phosphorylation (OXPHOS) is the final stage of cellular respiration, which is 
counted as the most abundant source of Adenosine Triphosphate (ATP) among the three 
processes of cellular respiration. These three processes are Glycolysis, the Krebs cycle, 
and Oxidative phosphorylation, respectively. The fundamental mechanism of oxidative 
phosphorylation is to synthesize ATP based on accumulated proton via the electron 
transport chain (ETC). Fumarate that is derived from this process can also enter the Krebs 
cycle. OXPHOS is regulated by cellular energy demand. Several factors tightly control 
the regulation of OXPHOS including the concentration of ATP and ADP, availability of 
oxygen, electron carriers (NADH and FADH2), and membrane potential. The dysfunction 
of oxidative phosphorylation is also mentioned. The method of analyzing the functional 
domain of the OXPHOS pathway, genes, and proteins, and assessing cellular function and 
energy that are utilized to detect abnormalities in the OXPHOS pathway are described in  order.  1. INTRODUCTION 
1.1. Overview of mitochondria 
Mitochondria are the organelles inside animal and plant cells. It plays a significant role in 
generating the energy known as ATP which provides cellular work. Two-over-three steps 
of cellular respiration take place in the mitochondria: the Krebs cycle and oxidative  phosphorylation (OXPHOS).  1           
 Figure 1. Animation of mitochondria structure (Margarida Azevedo, 2015) 
The mitochondrion is one of three double-membrane organelles inside the cell. The inner 
membrane has a phospholipid structure containing hydrophobic tails and hydrophilic 
heads with many proteins embedded. 
The OXPHOS discussed in this review mainly occurs in the inner membrane of 
mitochondria. Besides, the intermembrane space is also involved as the container of  protons. 
1.2. Overview of oxidative phosphorylation 
1.2.1. Definition of oxidative phosphorylation 
OXPHOS is a cascade of redox reactions that occur in mitochondria. This is the final stage 
of cellular respiration, which is counted for the most abundant ATP generated. It causes 
the accumulation of protons in matrix space. Two components that build up a mechanism 
are the electron transport chain and chemiosmosis. In the mechanism, the electron 
transport chain is composed of four complexes marked as complex I-IV (proteins), and 
organic molecules (Ubiquinone/Q/CoQ, and cytochrome c) are embedded in the inner 
membrane of mitochondria. Chemiosmosis has the enzyme ATP synthase combined with 
proton to produce ATP at the end.  2         
Figure 2. The electron transport chain in the inner membrane of mitochondria (John P.  Rafferty, 2017) 
The first electron acceptor is Nicotinamide Adenine Dinucleotide (NADH) which is taken 
from the other stage of cellular respiration. The second electron acceptor is Flavin Adenine 
Dinucleotide (FADH2). In chemiosmosis, the final electron acceptor is oxygen which is 
derived from inhalation. By that means, if the living organism does not intake oxygen 
from the outside into the body, the electron transport chain will be stopped. It is considered 
an aerobic process. OXPHOS involved three main steps including the delivery of electrons 
by NADH and FADH2, the movement of electrons to complex III, and the reduction of  oxygen into water (Figure 2). 
NADH and FADH2 are oxidized at complex I and complex II, respectively, to give NAD+, 
FAD+, and electrons. After that, the electrons will move to Ubiquinone Q which is a 
mediate molecular in the system. A part of them acts as the energy for pumping proton 
from the matrix to the intermembrane space against the gradient, called the proton-motive 
force. In complex II, there is also the formation of fumarate derived from succinate that 
can enter the Krebs cycle. Complex III is also involved in proton pumping, which forces 
the proton H+ out of the matrix to intermembrane space. And the electrons keep moving 
to the cytochrome c. After the electrons are passed through complex I/complex II to CoQ 
to Complex III and to cytochrome C, it arrives complex IV at which steps the oxygen will 
receive the electrons to reduce into oxygen ion. The oxygen ion then combines with the  proton to form water.  3          1.2.2. Synthesis of ATP 
Proton moves back from intermembrane space into the matrix to combine with ATP 
synthase and make ATP. However, protons cannot pass through the hydrophobic tail of the 
membrane. The ATP synthase provides a canal for the proton to move in the matrix. The 
proton is a catalyst to add the phosphate (Pi) to Adenosine Diphosphate (ADP) to become 
ATP in a phosphorylation reaction.   
Figure 3. ATP synthase pumps protons back to generate ATP (Klaus Hoffmeier, 2020) 
Because the OXPHOS pathway is a crucial process for energy production, abnormal 
OXPHOS can lead to health problems and energy-related diseases. In this review, the 
regulation of the OXPHOS pathway is discussed initially. Several factors tightly control 
the regulation of OXPHOS that are mentioned including the concentration of ATP and 
ADP, availability of oxygen, electron carriers (NADH and FADH2), and membrane 
potential. To detect the abnormalities and dysregulation of the OXPHOS pathway, the 
method of analyzing the functional domain of the OXPHOS pathway, genes, and proteins, 
and assessing cellular function and energy are described in order.    4       
2. REGULATION OF OXIDATIVE PHOSPHORYLATION 
Aerobic oxidative pathways that lead to electron transfer to oxygen are accompanied by 
OXPHOS. OXPHOS provides tremendous energy efficiency of catabolism since it 
produces more than 15 times the ATP generated by anaerobic glycolysis (Alberts et al., 
2002). Therefore, it is crucial to regulate ATP production by OXPHOS to match the cell’s 
fluctuating demand for ATP. The OXPHOS is regulated by several factors including 
concentration of ADP and ATP, availability of oxygen, electron carriers (NADH and 
FADH2), and membrane potential. 
In tight regulation, the rate of respiration in mitochondria is generally limited by the 
availability of ADP as a phosphorylation substrate. A measure of the energy state of cells 
is the intracellular concentration of ADP. The mass-action ratio of the ATP-ADP system, 
[ATP]/([ADP][Pi]), is another related measure. Normally, this ratio is quite high for the 
almost full phosphorylation of the ATP-ADP system. The rate of ATP breakdown into 
ADP and Pi increases as the rate of any energy-intensive process, such as protein synthesis, 
results in a lowering in the mass-action ratio. The rate of respiration increases as there is 
more ADP available for OXPHOS, which results in ATP regeneration. This continues until 
the mass-action ratio returns to its normal high level, at which point respiration slows 
again. Even with significant fluctuations in energy demand, the [ATP]/([ADP][Pi]) ratio 
in most tissues fluctuates slightly because the rate of oxidation of cellular fuels is regulated 
with such sensitivity and precision. In other words, ATP is only produced fast as it is used 
in energy-requiring cellular activities. 
ATP synthase catalyzes the reverse of ATP synthesis as an ATP-driven proton pump. When 
a cell is deprived of oxygen, electron transfers to oxygen and the pumping of protons 
ceases leading to the proton-motive force collapsing. Additionally, the main source of ATP 
becomes glycolysis, and the pyruvic or lactic acid thus formed lowers the pH in the cytosol 
and the mitochondrial matrix. Under these conditions, the ATP synthase could operate in 
reverse, hydrolyzing ATP to pump protons outward and causing a disastrous drop in ATP 
levels. This is prevented by a small (84 amino acids) protein inhibitor, IF1. At a pH lower 
than 6.5, IF1 inhibits the ATPase activity in its dimeric form. It binds to the ab interface 
of the subunits in the diphosphate (ADP) conformation (αADP and βADP), freezing the  5         
two F1 complexes and thereby blocking ATP hydrolysis. When aerobic metabolism 
resumes, production of pyruvic acid slows, the pH of the cytosol rises, the IF1 dimer is 
destabilized, and the inhibition of ATP synthase is lifted. 
ETC is in the inner mitochondrial membrane that is responsible for generating a proton 
gradient across the membrane. This gradient is then used to drive the synthesis of ATP 
through OXPHOS. During OXPHOS, NADH and FADH2 transfer electrons to the ETC, 
which then uses the energy from these electrons to pump protons across the inner 
mitochondrial membrane, creating an electrochemical gradient that drives ATP synthesis 
through chemiosmosis. NADH and FADH2 have different effects on OXPHOS. NADH 
delivers electrons to complex I of the ETC, which pumps more protons than complex II 
and therefore contributes more to the proton gradient and ATP synthesis. FADH2 delivers 
electrons to complex II, which does not pump as many protons as complex I, resulting in  less ATP production. 
As mentioned above, protons are pumped across the inner mitochondrial membrane as 
electrons pass through the electron transfer chain creating a proton gradient. This 
electrochemical gradient includes contributions from both a membrane potential and a pH 
gradient. The pH gradient drives H+ return to the matrix and OH- out of the matrix, 
thereby reinforcing the effect of the membrane potential, which acts to attract any positive 
ion into the matrix and push any negative ion out (Figure 4). A large amount of free energy 
is released that provides the basis for ATP production in the matrix. The effective ATPADP 
exchange between the mitochondrion and the cytosol, which maintains the cell's ATP pool 
in a highly charged state, is one of the active transport processes that are driven by the 
transmembrane electrochemical gradient. The high ratio of ATP to its hydrolysis products 
that results makes the free-energy change for ATP hydrolysis exceedingly favorable, 
allowing this hydrolysis reaction to drive a significant portion of the cell's energy- consuming functions.  6         
Figure 4. The two components of the electrochemical proton gradient (Alberts et al.,  2002). 
The primary sources of the electrons that enter the mitochondrial electron-transport chain 
are glycolysis, fatty acid degradation, and the citric acid cycle. These pathways have 
interlocking and concerted regulatory mechanisms that allow them to function together in 
an economical and self-regulating manner to produce ATP and biosynthetic precursors. It 
can be seen that the control of glycolysis and the citric acid cycle is coordinated with the 
demand for OXPHOS. The rate of electron transfer and OXPHOS increases whenever 
ATP consumption increases. The influx of electrons into the respiratory chain also rises 
simultaneously with an increase in the rate of pyruvate oxidation via the citric acid cycle. 
These events can in turn evoke a rise in glycolysis, which would increase the rate of 
pyruvate synthesis. Acceptor control inhibits electron transport when the conversion of 
ADP to ATP reduces the ADP concentration, and thus OXPHOS. Because ATP is an 
allosteric inhibitor of the glycolytic enzyme phosphofructokinase-1 (PFK-1), glycolysis 
and the citric acid cycle are also slowed. The first intermediate of the citric acid cycle, 
citrate, also inhibits PFK-1. Citrate builds up inside mitochondria and overflows into the 
cytosol when the cycle is "idling," (Lehninger et al., 2008). A concerted allosteric 
inhibition of PFK-1 is produced when the levels of ATP and citrate both increases. This 
inhibition is higher than the sum of the separate effects and slows glycolysis.  7         
3. DYSREGULATION OF THE PATHWAY IN HUMAN DISEASES 
3.1. Oxidative phosphorylation in the human body 
3.1.1. The oxidative phosphorylation (OXPHOS) pathway and its role in cells  and the human body 
The OXPHOS pathway is the process of producing ATP by using the energy released from 
the oxidation of organic compounds in the cells of the body. This process occurs in the 
inner membrane of mitochondria within the cell. In the OXPHOS pathway, NADH and 
FADH2 molecules produced in the TCA cycle are transferred to the mitochondrial ETC 
and release electrons. These electrons move through a series of complexes (I, II, III, and 
IV) in the ETC, creating potential electron energy. This electron energy pumps protons 
(H+) from the mitochondrial matrix to the inner membrane, creating a higher proton 
concentration outside the inner membrane. The concentration of protons creates an 
electrochemical gradient, and the ATP synthase enzyme uses this energy to produce ATP  from ADP and Pi. 
The OXPHOS pathway provides energy for basic cellular processes, including the 
conversion and synthesis of organic compounds, ion transport, and driving chemical 
reactions. The OXPHOS process is also related to energy conversion in the body, 
especially in maintaining body temperature and organ function. In addition, pathologies 
related to the OXPHOS pathway can cause health problems, including genetic and  cardiovascular diseases. 
3.1.2. The interest of scientists in studying the abnormalities and dysregulation 
of the OXPHOS pathway in diseases 
The OXPHOS pathway is an important cellular process for energy production. However, 
when the OXPHOS pathway is abnormal or dysregulated, it can lead to energy-related 
diseases such as diabetes, cardiovascular disease, Parkinson's disease, and depression. 
Therefore, researching abnormalities and dysregulation of the OXPHOS pathway is very 
important and has attracted the attention of many scientists.  8       
Scientists are studying factors that affect the OXPHOS pathway, such as genes, proteins, 
bacteria, and cells. They are also looking for treatment methods for diseases related to 
abnormalities and dysregulation of the OXPHOS pathway. 
Recent research has identified factors that can modulate the OXPHOS pathway and 
improve energy-related diseases. For example, certain foods and nutrients have been 
shown to affect the OXPHOS pathway. In addition, treatment methods for diabetes, 
cardiovascular disease, and depression are also being developed based on new knowledge 
about the OXPHOS pathway. In summary, abnormalities, and dysregulation of the 
OXPHOS pathway are important and promising research topics for scientists. New 
findings in this field may provide new methods to treat energy-related diseases and 
improve the quality of life for humans. 
3.2. Methods to detect abnormalities and dysregulation of the OXPHOS pathway 
3.2.1. The method of analyzing the functional domain of the OXPHOS pathway 
The method of analyzing the functional domain of the OXPHOS pathway is a technique 
that analyzes the activities and functions of molecules and structures related to the 
OXPHOS system in cells. This method uses modern tools and techniques such as 
proteomics, transcriptomics, metabolomics, and cell electrochemistry to measure changes 
in the functional domain of the OXPHOS system. The process of analyzing the functional 
domain of the OXPHOS pathway includes five main steps, which are (1) measuring the 
activity of electron complexes that analyzing the activity of electron complexes using 
spectroscopic or cell electrochemistry methods to determine changes in their activity; (2) 
analyzing protein and gene concentrations for measuring protein and gene concentrations 
to detect changes in the functional domain of the OXPHOS system; (3) evaluating ATP 
productivity and oxygen consumption which can measure ATP productivity and oxygen 
consumption to determine the efficiency of the OXPHOS system; (4) analyzing the ability 
to metabolize by using metabolomics to measure changes in intermediate metabolites in 
the OXPHOS process; and (5) evaluating interactions between molecules and structures 
through using proteomics methods to determine interactions between molecules and 
structures in the OXPHOS system. Furthermore, the method of analyzing the functional  9         
domain of the OXPHOS pathway is an important tool for understanding the activity of the 
OXPHOS system and how it relates to health issues. 
However, the functional domain analysis method for detecting abnormalities and 
dysregulation of the OXPHOS pathway still has both advantages and limitations. For its 
advantages, it can provide information about the activity of components of the OXPHOS 
pathway. Specifically, functional domain analysis allows the determination of the function 
of components of the OXPHOS pathway, such as ATP production systems and oxidative 
and reductive processes involved in energy generation. Moreover, it also can enable the 
detection of gene and protein mutations which can detect gene and protein mutations 
related to OXPHOS by measuring their activity in the pathway. Lastly, functional domain 
analysis allows the assessment of the effects of environmental factors and drugs on the 
activity of the OXPHOS pathway. On the other hand, the functional domain analysis 
method still gains drawbacks, which requires the use of complex techniques such as 
measuring intermediate compound concentrations to determine the activity of components 
in the OXPHOS pathway. In addition, to obtain accurate results, functional domain 
analysis must be performed by experts with experience in this field, and the cost of this 
method is relatively high, so it is not always widely used in practice. 
3.2.2. The method of analyzing genes 
The method of gene analysis is a technique for analyzing changes in DNA related to the 
OXPHOS pathway. It allows for the detection of abnormalities and regulatory imbalances 
in the expression of genes encoding proteins involved in OXPHOS. This method can be 
performed in several ways, including (1) Whole genome sequencing will analyse the 
entire genome sequence to identify variations in genes related to the OXPHOS system. 
This is an expensive and time-consuming method, but it can detect rare or unclear 
variations; (2) Gene fragment analysis which evaluates gene fragments related to the 
OXPHOS system to identify variations such as single nucleotide polymorphisms (SNPs) 
or larger variations such as insertions or deletions. This method is faster and cheaper than 
whole genome sequencing, or (3) Gene expression analysis determines regulatory 
imbalances in the production of proteins related to the OXPHOS system. This method can  10       
be performed using tools such as microarrays or RNA sequencing to measure the  expression levels of genes. 
The results of gene analysis can help identify variations in genes related to OXPHOS, 
thereby detecting abnormalities and regulatory imbalances in the OXPHOS system. Gene 
analysis also allows researchers to assess the impact of these variations on the activity of 
the OXPHOS system and provide solutions to improve the health status of cells and the  body. 
This method provides a comprehensive understanding of the genetic factors involved in 
the OXPHOS pathway, which is essential for developing effective treatments and 
therapies for related diseases. Moreover, it allows for the identification of specific genetic 
mutations that may cause abnormalities in the OXPHOS pathway, thereby enabling early 
detection and intervention before the onset of severe symptoms. The method is also highly 
sensitive and can detect even minor changes in gene expression or activity, providing 
valuable insights into the underlying mechanisms of the pathway. Besides these benefits, 
the method may be limited by its inability to account for non-genetic factors that may 
influence the OXPHOS pathway, such as environmental factors or epigenetic 
modifications. In addition, the interpretation of results may be complicated by the complex 
interactions between multiple genes and pathways involved in the OXPHOS system. 
Overall, while the method of analyzing gene function has its advantages and limitations, 
it remains an essential tool for investigating the underlying genetic factors contributing to 
abnormalities and imbalances in the OXPHOS pathway. 
3.2.3. The method of analyzing proteins 
The protein analysis method is a technique that allows for the analysis of changes in 
proteins related to the OXPHOS pathway. It enables the detection of abnormalities and 
regulatory imbalances in the production of proteins related to OXPHOS. There are three 
major ways to perform this technique, which are (1) Western blotting; (2) 
Immunoprecipitation; and (3) Mass spectrometry. In Western blotting, this method allows 
for the analysis of the level of a specific protein by using a specific antibody for that 
protein. These techniques provide information on the level and size of the protein, while  11         
immunoprecipitation allows for the separation of a specific protein from a protein mixture 
using a specific antibody. Once the protein has been separated, it can be used to analyze 
the different parameters of that protein in detail. Through mass spectrometry, it requires 
the analysis of the protein composition of a sample by measuring the mass of each 
individual protein. This is a powerful method and is widely used in protein and energy 
metabolism research. In conclusion, the results of protein analysis can help identify 
abnormalities and regulatory imbalances in the production of proteins related to the 
OXPHOS pathway. This method also allows researchers to assess the impact of these 
changes on the activity of the OXPHOS system and provide solutions to improve the 
health status of cells and the body. 
The method provides direct information on the expression and activity of proteins 
involved in the OXPHOS pathway, which can help identify potential targets for 
therapeutic interventions. Furthermore, it can be used to identify post-translational 
modifications of proteins, such as phosphorylation or acetylation, which can provide 
insights into the regulation of the pathway. This method is highly specific, which allows 
for the identification of individual protein isoforms and their expression levels. In contrast, 
this technique still has some disadvantages. First, it may be limited by the availability and 
quality of samples, which can be affected by factors such as sample collection, storage, 
and processing. Secondly, it may be challenging to isolate and quantify specific proteins 
of interest from complex biological samples, such as tissue or blood. Next, the 
interpretation of results can be challenging due to the complexity of the OXPHOS 
pathway and the interactions between different proteins and pathways involved. 
Overall, while the method of protein analysis has its advantages and limitations, it remains 
a valuable tool for investigating the expression and activity of proteins involved in the 
OXPHOS pathway and identifying potential targets for therapeutic interventions. 
3.2.4. The method of evaluating cellular functions and energy 
Assessing cellular function and energy is a common method to detect abnormalities and 
dysregulation in the OXPHOS pathway. These assessment methods may include: (1) Cell 
energy measurement that estimates the energy produced in cells, through measuring  12       
changes in ATP and NADH levels. Changes in ATP and NADH levels can indicate changes 
in OXPHOS pathway function; (2) Redox ratio can evaluate the balance between the 
oxidation and reduction processes in cells. Imbalances may indicate abnormalities in 
OXPHOS function; (3) Mitochondrial diameter measurement evaluates the size of 
mitochondria in cells which indicates changes in the OXPHOS pathway function; and (4) 
Mitochondrial protein distribution ratio measurement can test the distribution ratio of 
mitochondrial proteins in cells, therefore can show the abnormalities in OXPHOS  function. 
The results from assessing cellular function and energy can help identify abnormalities 
and dysregulation in the OXPHOS pathway. This assessment also allows researchers to 
evaluate the impact of these changes on the OXPHOS system and to develop solutions to 
improve cellular and body health. Through the evaluation of cellular functions and energy, 
it provides information on cellular and energy metabolism that can reveal changes in the 
OXPHOS pathway due to disease or genetic mutations and can be used to evaluate the 
efficacy of potential therapeutic interventions on cellular and mitochondrial functions. 
Moreover, this technique allows for the assessment of various components of 
mitochondrial function, including oxygen consumption, ATP synthesis, and electron 
transport chain activity. Enables the monitoring of changes in mitochondrial function over 
time and under different experimental conditions is also a bonus point for this technique. 
However, this can be technically challenging and require specialized equipment and 
expertise. The sensitivity and specificity of these methods can be affected by various 
factors, such as sample quality and the presence of contaminants. Next, measurements can 
be affected by extracellular factors, such as oxygen and nutrient availability, which can 
vary in different experimental conditions.      4. CONCLUSION 
In conclusion, oxidative phosphorylation plays a key role in the whole cellular respiration 
process, where combined action of the electron transport chain and chemiosmotic 
coupling result in ATP production. It is regulated by a cell's energy needs, and thus the  13         
ratio of ADP to ATP. Since the abnormality and dysregulation, there are some techniques 
used to detect, which are by analyzing the functional domain of the OXPHOS pathway, 
by evaluation of genes or proteins in the human body, or by estimating the function and 
energy level of cellular. However, besides the benefits of each method, there are still 
disadvantages in applying treatment.        14        REFERENCES 
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