They absorb photons with high efficiency so that whenever a pigment in the photosynthetic reaction center absorbs a photon, an electron from the pigment is excited and transferred to another molecule almost instantaneously. Step 3. oxidative phosphorylation input. When the protein gramicidin is integrated into a membrane, an H+ channel forms and the membrane becomes very permeable to protons (H+ ions). Other molecules that would otherwise be used to harvest energy in glycolysis or the citric acid cycle may be removed to form nucleic acids, amino acids, lipids, or other compounds. What are the inputs of oxidative phosphorylation? Plants sequester these proteins in chloroplasts, but bacteria, which dont have organelles, embed them in their plasma membranes. In bacteria, both glycolysis and the citric acid cycle happen in the cytosol, so no shuttle is needed and 5 ATP are produced. The electrons are transferred to molecular oxygen from an energy precursor that is produced in a citric acid cycle through the use of enzymes. L.B. Labels may be used more than once. Fewer ATP molecules are generated when FAD+ acts as a carrier. Cyanide, and that weight control pill all cause the normal respiration to function abnormally. PS I gains a positive charge as a result of the loss of an excited electron and pulls the electron in plastocyanin away from it. Image of the electron transport chain. The answer is the captured energy of the photons from the sun (Figure 5.59), which elevates electrons to an energy where they move downhill to their NADPH destination in a Z-shaped scheme. -A bond must be broken between an organic molecule and phosphate before ATP can form. Cyanide inhibits cytochrome c oxidase, a component of the electron transport chain. The electron transport chain is a series of protein complexes and electron carrier molecules found within the mitochondrial membrane in eukaryotic cells. The LibreTexts libraries arePowered by NICE CXone Expertand are supported by the Department of Education Open Textbook Pilot Project, the UC Davis Office of the Provost, the UC Davis Library, the California State University Affordable Learning Solutions Program, and Merlot. This process is similar to oxidative phosphorylation in several ways. Label the arrows indicating electrons carried by NADH. Remember that all aqueous solutions contain a small amount of hydronium (HO) and hydroxide (OH) due to autoionization. 2 ATPs are used up by glycolysis this then begins the oxidative process of glycolysis. In animals, oxygen enters the body through the respiratory system. What is the role of NAD+ in cellular respiration. Direct link to Abdul Mannan's post How much electron NADH & . One ATP (or an equivalent) is also made in each cycle. Direct link to DonaShae's post Cellular Respiration happ, Posted 6 years ago. Drag the labels on the left onto the diagram to identify the compounds that couple each stage. Direct link to Ellie Bartle's post Substrate level is the 'd, Posted 5 years ago. Both electron transport and ATP synthesis would stop. In the last stage of cellular respiration, oxidative phosphorylation, all of the reduced electron carriers produced in the previous stages are oxidized by oxygen via the electron transport chain. Oxidative phosphorylation is where most of the ATP actually comes from. Oxidative phosphorylation is made up of two closely connected components: the electron transport chain and chemiosmosis. In acetyl CoA formation, the carbon-containing compound from glycolysis is oxidized to produce acetyl CoA. NAD+ is reduced to NADH. Net Input: NADH, ADP, O Net Output: NAD, ATP, and Water Not Input or Output: Pyruvate, Glucose, Acetyl CoA, Coenzyme A and CO. During strenuous exercise, anaerobic conditions can result if the cardiovascular system cannot supply oxygen fast enough to meet the demands of muscle cells. These electrons come originally from glucose and are shuttled to the electron transport chain by electron carriers, To see how a glucose molecule is converted into carbon dioxide and how its energy is harvested as ATP and, Glycolysis can take place without oxygen in a process called, Each stage of cellular respiration is covered in more detail in other articles and videos on the site. [(Cl3CCO)2O], [(CH3CO)2O]\left[ \left( \mathrm { CH } _ { 3 } \mathrm { CO } \right) _ { 2 } \mathrm { O } \right] So, where does oxygen fit into this picture? The energy from this oxidation is stored in a form that is used by most other energy-requiring reactions in cells. NADH and FADH2 made in the citric acid cycle (in the mitochondrial matrix) deposit their electrons into the electron transport chain at complexes I and II, respectively. are not subject to the Creative Commons license and may not be reproduced without the prior and express written Acetyl CoA can be used in a variety of ways by the cell, but its major function is to deliver the acetyl group derived from pyruvate to the next pathway in glucose catabolism. O b) It can occur only in the mitochondrion. Also within the stroma are stacked, flattened disks known as thylakoids which are defined by their thylakoid membranes. Direct link to bart0241's post Yes glycolysis requires e, Posted 3 years ago. F) 4 C When a compound accepts (gains) electrons, that compound becomes ________. Carbon inputs to oxidative phosphorylation All six of the carbon atoms that enter glycolysis in glucose are released as molecules of CO 2during the first three stages of cellular respiration. Correct: Describe the relationships of glycolysis, the citric acid cycle, and oxidative phosphorylation in terms of their inputs and outputs. Photosynthesis is an energy capture process found in plants and other organisms to harvest light energy and convert it into chemical energy. Of the following lists of electron transport compounds, which one lists them in order from the one containing electrons with the highest free energy to the one containing electrons with the lowest free energy? When a compound donates (loses) electrons, that compound becomes ___________. Drag each compound to the appropriate bin. (Note that not all of the inputs and outputs of oxidative phosphorylation are listed.) The entirety of this process is called oxidative phosphorylation. This reaction is called photo-induced charge separation and it is a unique means of transforming light energy into chemical forms. In the electron transport chain, the free energy from the series of reactions just described is used to pump hydrogen ions across the membrane. -An enzyme is required in order for the reaction to occur Direct link to richie56rich's post How much H2O is produced , Posted 4 years ago. Oxidative phosphorylation is the process in which ATP is formed as a result of the transfer of electrons from NADH or FADH 2 to O 2 by a series of electron carriers. The chloroplasts membrane has a phospholipid inner membrane, a phospholipid outer membrane, and a region between them called the intermembrane space (Figure 5.61). Overall, in living systems, these pathways of glucose catabolism extract about 34 percent of the energy contained in glucose. The electron transport chain is a series of proteins embedded in the inner mitochondrial membrane. if glycolysis requires ATP to start how did the first glycolysis in history happen? For the growing plant, the NADPH and ATP are used to capture carbon dioxide from the atmosphere and convert it (ultimately) into glucose and other important carbon compounds. Oxygen continuously diffuses into plants for this purpose. When protons flow through ATP synthase, they cause it to turn (much as water turns a water wheel), and its motion catalyzes the conversion of ADP and Pi to ATP. Another factor that affects the yield of ATP molecules generated from glucose is that intermediate compounds in these pathways are used for other purposes. In plants and algae, the pigments are held in a very organized fashion complexes called antenna proteins that help funnel energy, through resonance energy transfer, to the reaction center chlorophylls. are licensed under a, Citric Acid Cycle and Oxidative Phosphorylation, Comparing Prokaryotic and Eukaryotic Cells, The Light-Dependent Reactions of Photosynthesis, Biotechnology in Medicine and Agriculture, Diversity of Microbes, Fungi, and Protists, Waterford's Energy Flow through Ecosystems. A) 2 C Glycolysis. The process of generating more ATP via the phosphorylation of ADP is referred to oxidative phosphorylation since the energy of hydrogen oxygenation is used throughout the electron transport chain. consent of Rice University. Answer: Net inputs are : NADH, ADP, O2 Net outpus are : NAD+, ATP, water Explanation: These compounds are involved in cellular respiration- Coenzyme A ,NADH ,ADP ,Acetyl CoA ,CO ,Glucose ,O ,ATP ,Pyruvate and water. The proton gradient generated by proton pumping during the electron transport chain is a stored form of energy. Instead, H. Overview diagram of oxidative phosphorylation. Anaerobic conditions and acetyl CoA formation The free energy from the electron transfer causes 4 protons to move into the mitochondrial matrix. The electron transport chain about to start churning out ATP. The effect of gramicidin on oxidative phosphorylation Decreases (or goes to zero): Rate of ATP synthesis, size of the proton gradient. The hydroxyethyl group is oxidized to an acetyl group, and the electrons are picked up by NAD +, forming NADH. Most affected people are diagnosed in childhood, although there are some adult-onset diseases. then you must include on every digital page view the following attribution: Use the information below to generate a citation. To log in and use all the features of Khan Academy, please enable JavaScript in your browser. In mitochondria, NADH/FADH2 are electron sources and H2O is their final destination. The energetically "downhill" movement of electrons through the chain causes pumping of protons into the intermembrane space by the first, third, and fourth complexes. The interior of a leaf, below the epidermis is made up of photosynthesis tissue called mesophyll, which can contain up to 800,000 chloroplasts per square millimeter. then you must include on every physical page the following attribution: If you are redistributing all or part of this book in a digital format, 4 CO2, 2 ATP, 6 NADH + H+, 2 FADH2. Direct link to Raya's post When the electron carrier, Posted 4 years ago. Direct link to Peony's post well, seems like scientis, Posted 6 years ago. Cellular respiration and a cell's demand for ATP This is the reason we must breathe to draw in new oxygen. start text, N, A, D, end text, start superscript, plus, end superscript, start text, F, A, D, H, end text, start subscript, 2, end subscript, 2, e, start superscript, minus, end superscript, 2, start text, H, end text, start superscript, plus, end superscript, start text, H, end text, start superscript, plus, end superscript. If you look in different books, or ask different professors, you'll probably get slightly different answers. Most of the ATP produced by aerobic cellular respiration is made by oxidative phosphorylation.The energy of O 2 released is used to create a chemiosmotic potential by pumping protons across a membrane. Textbook content produced by OpenStax is licensed under a Creative Commons Attribution License . In fermentation, the NADH produced by glycolysis is used to reduce the pyruvate produced by glycolysis to either lactate or ethanol. When I learned about it for the first time, I felt like I had tripped and fallen into a can of organic-chemistry-flavored alphabet soup! the source of the electrons H2O for photosynthesis versus NADH/FADH2 for oxidative phosphorylation, direction of proton pumping into the thylakoid space of the chloroplasts versus outside the matrix of the mitochondrion, movement of protons during ATP synthesis out of the thylakoid space in photosynthesis versus into the mitochondrial matrix in oxidative phosphorylation. [1] 5. The electron transport chain would speed up, and the gradient would become stronger, The electron transport chain would stop, and the gradient would decrease, Both the electron transport chain and the gradient would stay the same, The electron transport chain would be re-routed through complex II, and the gradient would become weaker. has not been pregnant previously; J.B. says he has never gotten a girl pregnant "that he knows of. Oxidative phosphorylation is a process involving a flow of electrons through the electron transport chain, a series of proteins and electron carriers within the mitochondrial membrane. Comparing the amount of ATP synthesis from NADH and FADH2 The components NAD + and NADH are common in both the oxidative phosphorylation pathway and the TCA cycle, while FAD and FADH 2 is bound tightly to the enzyme SDH (Korla and Mitra, 2014).The reduced molecules NADH and FADH 2 serve as electron donors for . With absorption of a photon of light by PS I, a process begins, that is similar to the process in PS II. Citric acid cycle. In most cases, a byproduct of the process is oxygen, which is released from water in the capture process. Try watching the, Posted 7 years ago. such as oxidative phosphorylation, MYC targets, and DNA repair. Unlike glycolysis, the citric acid cycle is a closed loop: The last part of the pathway regenerates the compound used in the first step. Oxidative phosphorylation" that the NADH and the FADH2 return to their "empty" forms NAD+ FADH2, the author meant FAD when referring to the "empty" forms, right? The electron transport chain (Figure 4.19 a) is the last component of aerobic respiration and is the only part of metabolism that uses atmospheric oxygen. Although necessary for multicellular life, in an ironic twist of fate aerobic cellular respiration is thought to also be responsible for the processes that end multicellular life. Within the inner chloroplast membrane is the stroma, in which the chloroplast DNA and the enzymes of the Calvin cycle are located. Electron Transport and Oxidative Phosphorylation; . The dark cycle is also referred to as the Calvin Cycle and is discussed HERE. But have you ever wondered why thats the case, or what exactly your body does with all that oxygen? Two net ATP are made in glycolysis, and another two ATP (or energetically equivalent GTP) are made in the citric acid cycle. Based on a lot of experimental work, it appears that four H. With this information, we can do a little inventory for the breakdown of one molecule of glucose: One number in this table is still not precise: the ATP yield from NADH made in glycolysis. These include Photosystem II (PS II), Cytochrome b6f complex (Cb6f), Photosystem I (PS I), and ATP synthase. At this point, the light cycle is complete - water has been oxidized, ATP has been created, and NADPH has been made. Remains the same: proton pumping rate, electron transport rate, rate of oxygen uptake The eight steps of the cycle are a series of chemical reactions that produces two carbon dioxide molecules, one ATP molecule (or an equivalent), and reduced forms (NADH and FADH2) of NAD+ and FAD+, important coenzymes in the cell. The reduced form of the electron acceptor in glycolysis is ________ . [(Cl3CCO)2O]\left[ \left( \mathrm { Cl } _ { 3 } \mathrm { CCO } \right) _ { 2 } \mathrm { O } \right] Another source of variance stems from the shuttle of electrons across the mitochondrial membrane. Drag each compound to the appropriate bin. Redox homeostasis is a delicate balancing act of maintaining appropriate levels of antioxidant defense mechanisms and reactive oxidizing oxygen and nitrogen species. What are the inputs and outputs of pyruvate oxidation? It was used until 1938 as a weight-loss drug. Except where otherwise noted, textbooks on this site The individual reactions can't know where a particular "proton" came from. It would be released as heat, and interestingly enough, some types of cells deliberately use the proton gradient for heat generation rather than ATP synthesis. The oxygen with its extra electrons then combines with two hydrogen ions, further enhancing the electrochemical gradient, to form water. The extra electrons on the oxygen ions attract hydrogen ions (protons) from the surrounding medium, and water is formed. Cellular locations of the four stages of cellular respiration, 1. NADH -- Fe-S of Complex I -- Q -- Fe-S of Complex III -- Cyt c-- Cyt a of Complex IV -- O2, Chapter 8 Dynamic Study Module: An Introducti, David N. Shier, Jackie L. Butler, Ricki Lewis, John David Jackson, Patricia Meglich, Robert Mathis, Sean Valentine, Jane B. Reece, Lisa A. Urry, Michael L. Cain, Peter V Minorsky, Robert B Jackson, Steven A. Wasserman. Use this diagram to track the carbon-containing compounds that play a role in these two stages. What are the inputs and outputs of oxidative phosphorylation? In organisms that perform cellular respiration, glycolysis is the first stage of this process. Direct link to Ivana - Science trainee's post Cellular respiration is o, Posted 6 years ago. All the components of the chain are embedded in or attached to the inner mitochondrial membrane. ATP and NADH are made. Overview of oxidative phosphorylation. Our mission is to improve educational access and learning for everyone. The roles of these complexes, respectively, are to capture light energy, create a proton gradient from electron movement, capture light energy (again), and use proton gradient energy from the overall process to synthesize ATP. This page titled 5.3: Energy - Photophosphorylation is shared under a CC BY-NC-SA license and was authored, remixed, and/or curated by Kevin Ahern, Indira Rajagopal, & Taralyn Tan. In the matrix, NADH and FADH2 deposit their electrons in the chain (at the first and second complexes of the chain, respectively). Oxidative phosphorylation. Direct link to tmytltr's post if glycolysis requires AT, Posted 4 years ago. Direct link to Medha Nagasubramanian's post Is oxidative phosphorylat, Posted 3 years ago. Eventually, the electrons are passed to oxygen, which combines with protons to form water. In the electron transport chain, electrons are passed from one molecule to another, and energy released in these electron transfers is used to form an electrochemical gradient. C) It is the formation of ATP by the flow of protons through a membrane protein channel. Direct link to tk12's post After oxidative phosphory, Posted 6 years ago. The electrons flow through the electron transport chain, causing protons to be pumped from the matrix to the intermembrane space. to function as the final electron acceptor in the electron transport chain, The effects of anaerobic conditions What are the inputs and outputs of pyruvate oxidation? Direct link to Ivana - Science trainee's post The free energy from the , Posted 6 years ago. Cellular respiration is a metabolic pathway that breaks down glucose and produces ATP. So. That's my guess and it would probably be wrong. Mitochondrial diseases are genetic disorders of metabolism. A . However, glycolysis doesn't require oxygen, and many anaerobic organismsorganisms that do . ATP levels would fall at first, decreasing the inhibition of PFK and increasing the rate of ATP production. .For example, oxidative phosphorylation generates 26 of the 30 molecules of ATP that are formed when glucose is completely oxidized to CO 2 and H 2 O. What would happen to the energy stored in the proton gradient if it weren't used to synthesize ATP or do other cellular work? Is oxidative phosphorylation the same as the electron transport chain? How much H2O is produced is the electron transport chain? For instance, hibernating mammals (such as bears) have specialized cells known as brown fat cells. Direct link to Herukm18's post What does substrate level, Posted 5 years ago. Besides the path described above for movement of electrons through PS I, plants have an alternative route that electrons can take. This flow of electrons allows the electron transport chain to pump protons to one side of the mitochondrial membrane. If a compound is not involved in oxidative phosphorylation, drag it to the "not input or output" bin. Failure in oxidative phosphorylation causes the deregulation of ATP-synthase activities in mitochondria and contributes to the elevation of oxidative stress and cell . The space within the thylakoid membranes are termed the thylakoid spaces or thylakoid lumen. Is it lungs? PQA hands the electron off to a second plastoquinone (PQB), which waits for a second electron and collects two protons to become PQH2, also known as plastoquinol (Figure \(\PageIndex{9}\)). Once the electron donor in glycolysis gives up its electrons, it is oxidized to a compound called ___________. Much more ATP, however, is produced later in a process called oxidative phosphorylation. As a result, the rate of cellular respiration, and thus ATP production, decreases. Direct link to syedashobnam's post the empty state of FADH2 , Posted 4 years ago. You, like many other organisms, need oxygen to live. Separate biochemical reactions involving the assimilation of carbon dioxide to make glucose are referred to as the Calvin cycle, also sometimes referred to as the dark reactions. TP synthesis in glycolysis: substrate-level phosphorylation After four electrons have been donated by the OEC to PS II, the OEC extracts four electrons from two water molecules, liberating oxygen and dumping four protons into the thylakoid space, thus contributing to the proton gradient. As electrons travel towards NADP+, they generate a proton gradient across the thylakoid membrane, which is used to drive synthesis of ATP. Sort the statements into the appropriate bin depending on whether or not they correctly describe some aspect of substrate-level phosphorylation in glycolysis. Oxidative phosphorylation occurs in the mitochondria. Pyruvate oxidation. ________ donates electrons to the electron transport chain. The electron transport chain forms a proton gradient across the inner mitochondrial membrane, which drives the synthesis of ATP via chemiosmosis. It takes two electrons, 1/2 O2, and 2 H+ to form one water molecule. Want to cite, share, or modify this book? Figure \(\PageIndex{6}\): Complexes in the thylakoid membrane. OpenStax is part of Rice University, which is a 501(c)(3) nonprofit. The chloroplasts are where the energy of light is captured, electrons are stripped from water, oxygen is liberated, electron transport occurs, NADPH is formed, and ATP is generated. A system so organized is called a light harvesting complex. Oxygen continuously diffuses into plants for this purpose. Direct link to SanteeAlexander's post I thought it was 38 ATPs , Posted 6 years ago. The steps in the photosynthesis process varies slightly between organisms. The input involved in glycolysis is two ATP (Adenosine triphosphate), two NAD+ and one glucose. Direct link to tyersome's post Remember that all aqueous, Posted 6 years ago. Along the way, some ATP is produced directly in the reactions that transform glucose. According to the amont of water molecules generated in chemiosmosis, all the hydrogen from the glucose should be used to form water, so do protons go into the mitochondria or mitochondria has extra protons itself? Direct link to Maulana Akmal's post how does the nadh from gl, Posted 7 years ago. It takes two turns of the cycle to process the equivalent of one glucose molecule. Net Input: Acetyl CoA, NAD+, ADP Net Output: Coenzyme A, CO2, NADH, ATP Not Input or Output: Pyruvate, Glucose, O2 (In the citric acid cycle, the two carbons from the acetyl group of acetyl CoA are oxidized to two molecules of CO2, while several molecules of NAD+ are reduced to NADH and one molecule of FAD is reduced to FADH2. A single glucose molecule consumes 2 ATP molecules and produces 4 ATP, 2 NADH, and two pyruvates. Most of the ATP generated during the aerobic catabolism of glucose, however, is not generated directly from these pathways. The first is known as PQA. The uneven distribution of H+ ions across the membrane establishes an electrochemical gradient, owing to the H+ ions positive charge and their higher concentration on one side of the membrane. Function. The third type of phosphorylation to make ATP is found only in cells that carry out photosynthesis. If you're seeing this message, it means we're having trouble loading external resources on our website. Symptoms of mitochondrial diseases can include muscle weakness, lack of coordination, stroke-like episodes, and loss of vision and hearing. Defects in oxidative phosphorylation, mitochondrial mechanisms, and calcium signalling are interconnected in a cascade sequence and ultimately lead to neurodegeneration in AD. Direct link to na26262's post if the volume of the inte, Posted 6 years ago. D) 5 C Simple diagram of the electron transport chain. But technically there should be net two protons left in cytosol and that's where I am puzzled. The electrons ultimately reduce O2 to water in the final step of electron transport. harvesting energy of the proton gradient by making ATP with the help of an ATP synthase. Electrons from NADH and FADH2 are passed to protein complexes in the electron transport chain. If a compound is not involved in oxidative phosphorylation, drag it to the "not input or output" bin. Fill in the following table to summarize the major inputs and outputs of glycolysis, the citric acid cycle, oxidative phosphorylation, and fermentation. is 29 years old and a self-employed photographer. You have just read about two pathways in glucose catabolismglycolysis and the citric acid cyclethat generate ATP. The four stages of cellular respiration do not function independently. Luckily, cellular respiration is not so scary once you get to know it. L.B. Pyruvate: Pyruvate is a molecule obtained as the main end-product of glycolysis performed in the cellular respiration mechanism. This photochemical energy is stored ultimately in carbohydrates which are made using ATP (from the energy harvesting), carbon dioxide and water. is the final electron acceptor of the electron transport chain. The ultimate replacement source of electrons is water, but water must lose four electrons and PS II can only accept one at a time. In this article, we'll examine oxidative phosphorylation in depth, seeing how it provides most of the ready chemical energy (ATP) used by the cells in your body. At the end of the electron transport system, the electrons are used to reduce an oxygen molecule to oxygen ions. Direct link to Dallas Huggins's post The new Campbell Biology , Posted 6 years ago. In eukaryotic cells, pyruvate is imported into the mitochondrial matrix for pyruvate oxidation. Glycolysis is an ancient metabolic pathway, meaning that it evolved long ago, and it is found in the great majority of organisms alive today ^ {2,3} 2,3. To summarize the light dependent reactions, let ' s look at the inputs and outputs: INPUTS: OUTPUTS: Light Energy: ATP: Water (H 2 O) NADPH : Oxygen Molecules (O 2) Study how the electrons are made available and what happens to them. Each turn of the cycle forms three high-energy NADH molecules and one high-energy FADH2 molecule. The output involved in glycolysis is four ATP, two NADH (nicotinamide adenine dinucleotide hydrogen) and two pyruvate molecules. A primary difference is the ultimate source of the energy for ATP synthesis. The oxygen liberated in the process is a necessary for respiration of all aerobic life forms on Earth. From the following compounds involved in cellular respiration, choose those that are the net inputs and net outputs of the citric acid cycle. It is easier to remove electrons and produce CO2 from compounds with three or more carbon atoms than from a two-carbon compound such as acetyl CoA. Drag the labels on the left to show the net redox reaction in acetyl CoA formation and the citric acid cycle. Oxygen sits at the end of the electron transport chain, where it accepts electrons and picks up protons to form water. FADH2 in the matrix deposits electrons at Complex II, turning into FAD and releasing 2 H+. It says above that NADH can't't cross the mitochondrial membrane, so there is some sort of shuttle protein. As electrons move down the chain, energy is released and used to pump protons out of the matrix and into the intermembrane space, forming a gradient. (Note that not all of the inputs and outputs of oxidative phosphorylation are listed.) Under anaerobic conditions (a lack of oxygen), the conversion of pyruvate to acetyl CoA stops. The mitochondria would be unable to generate new ATP in this way, and the cell would ultimately die from lack of energy. Such a compound is often referred to as an electron donor. Overall, what does the electron transport chain do for the cell? It undergoes oxidative phosphorylation that leads to ATP production. These reactions take place in specialized protein complexes located in the inner membrane of the mitochondria of eukaryotic organisms and on the inner part of the cell membrane of prokaryotic organisms. cytosol. Cb6f drops the electron off at plastocyanin, which holds it until the next excitation process begins with absorption of another photon of light at 700 nm by PS I. This electron must be replaced. Drag each compound to the appropriate bin. Photons from the sun interact with chlorophyll molecules in reaction centers in the chloroplasts (Figures and ) of plants or membranes of photosynthetic bacteria. How is ATP produced in cellular respiration? Acetyl CoA and Oxalo, Posted 3 years ago. b) glycolysis, citric acid cycle, electron transport chain, pyruvate oxidation. NADH and FADH2 are both electron carriers that donate their electrons to the electron transport chain. Oxidative phosphorylation is made up of two closely connected components: the electron transport chain and chemiosmosis. Electron transport and oxidative phosphorylation is the third and final step in aerobic cellular respiration. Note that not all electron transport compounds in the electron transport chain are listed.a) FMN of Complex I -- Q -- Fe-S of Complex II -- FADH2 -- Fe-S of Complex III -- Cyt c -- Cyt a of Complex IV -- O2b) FADH2 -- FMN of Complex I -- Fe-S of Complex II -- Q -- Fe-S of Complex III -- Cyt c -- Cyt a of Complex IV -- O2c) O2 -- Cyt a of Complex IV -- Cyt c -- Fe-S of Complex III -- Q -- Fe-S of Complex II -- FMN of Complex I -- FADH2d) FADH2 -- FMN of Complex I -- Fe-S of Complex II -- Fe-S of Complex III -- Q -- Cyt a of Complex IV -- Cyt c -- O2, C) FADH2 -- FMN of Complex I -- Fe-S of Complex II -- Q -- Fe-S of Complex III -- Cyt c -- Cyt a of Complex IV -- O2.