b. NADH Our mission is to improve educational access and learning for everyone. Enter the email address you signed up with and we'll email you a reset link. If you're seeing this message, it means we're having trouble loading external resources on our website. A . Citric Acid Cycle ("Krebs cycle"), this step is the metabolic furnace that oxidizes the acetyl CoA molecules and prepares for oxidative phosphorylation by producing high energy coenzymes for the electron transport chain - "energy harvesting step" - Input = one molecule of acetyl CoA - Output = two molecules of CO2, three molecules of NADH, one . All of the electrons that enter the transport chain come from NADH and FADH, Beyond the first two complexes, electrons from NADH and FADH. The development of celluar respiration began as a simple inefficient system progressing to it's current incarnation. All the components of the chain are embedded in or attached to the inner mitochondrial membrane. Book: Biochemistry Free For All (Ahern, Rajagopal, and Tan), { "5.01:_Basics_of_Energy" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "5.03:_Energy_-_Photophosphorylation" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "5.2:_Electron_Transport_and_Oxidative_Phosphorylation" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()" }, { "00:_Front_Matter" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "01:_In_The_Beginning" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "02:_Structure_and_Function" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "03:_Membranes" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "04:_Catalysis" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "05:_Energy" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "06:_Metabolism" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "07:_Information_Processing" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "08:_Basic_Techniques" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "09:_Chapter_10" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "10:_Chapter_11" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "11:_Point_by_Point" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "zz:_Back_Matter" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()" }, [ "article:topic", "authorname:ahern2", "Photophosphorylation", "showtoc:no", "license:ccbyncsa" ], https://bio.libretexts.org/@app/auth/3/login?returnto=https%3A%2F%2Fbio.libretexts.org%2FBookshelves%2FBiochemistry%2FBook%253A_Biochemistry_Free_For_All_(Ahern_Rajagopal_and_Tan)%2F05%253A_Energy%2F5.03%253A_Energy_-_Photophosphorylation, \( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}}}\) \( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash{#1}}} \)\(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\) \(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\)\(\newcommand{\AA}{\unicode[.8,0]{x212B}}\), 5.2: Electron Transport and Oxidative Phosphorylation, Kevin Ahern, Indira Rajagopal, & Taralyn Tan, Electron transport: chloroplasts vs mitochondria, http://biochem.science.oregonstate.edu/content/biochemistry-free-and-easy, status page at https://status.libretexts.org, a membrane associated electron transport chain. So, where does oxygen fit into this picture? Overall, what does the electron transport chain do for the cell? 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. 3 domains of life proposed by Carl Woese 1970s 1 bacteria 2 Archaea prokaryotes 3 eukarya protozoa algae fungi plants animals cells nutrients cell wall motility bacteria s yes common archaea single in organic protozoa sing yes common no usual algae both photo synth yes rare fungi yes rare organic helminths m no always 9th organic which organisms can be pathogens bacteria . However, the amount of ATP made by electrons from an NADH molecule is greater than the amount made by electrons from an FADH2 molecule. Direct link to Peony's post well, seems like scientis, Posted 6 years ago. 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. Direct link to Nick Townsend's post Just like the cell membra, Posted 7 years ago. The Describe the relationships of glycolysis, the citric acid cycle, and oxidative phosphorylation in terms of their inputs and outputs. 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. c. NAD+ The four stages of cellular respiration do not function independently. Approximately how much more free energy is supplied to the electron transport chain by NADH than by FADH2? In bacteria, both glycolysis and the citric acid cycle happen in the cytosol, so no shuttle is needed and 5 ATP are produced. 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. https://med.libretexts.org/Bookshelves/Anatomy_and_Physiology/Book%3A_Anatomy_and_Physiology_(Boundless)/21%3A_Respiratory_System/21.9%3A_Gas_Exchange/21.9B%3A_Internal_Respiration. It may also be vestigial; we may simply be in the process of evolving towards use only of higher-energy NADH and this is the last enzyme that has . Direct link to Taesun Shim's post Yes. An intermediate Oxygen Evolving Complex (OEC) contains four manganese centers that provide the immediate replacement electron that PSII requires. 2 ATPs are used up by glycolysis this then begins the oxidative process of glycolysis. (a) The electron transport chain is a set of molecules that supports a series of oxidation-reduction reactions. Through oxygen and glucose, ATP is ultimately created through the phosphorylation of ADP. 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! You have just read about two pathways in glucose catabolismglycolysis and the citric acid cyclethat generate ATP. With absorption of a photon of light by PS I, a process begins, that is similar to the process in PS II. Photons from the sun interact with chlorophyll molecules in reaction centers in the chloroplasts (Figures \(\PageIndex{1}\) and \(\PageIndex{2}\)) of plants or membranes of photosynthetic bacteria. I) 4 C. Net redox reaction in acetyl CoA formation and the citric acid cycle In mitochondria, pyruvate will be transformed into a two-carbon acetyl group (by removing a molecule of carbon dioxide) that will be picked up by a carrier compound called coenzyme A (CoA), which is made from vitamin B5. The electrons ultimately reduce O2 to water in the final step of electron transport. But have you ever wondered why thats the case, or what exactly your body does with all that oxygen? Direct link to tyersome's post Remember that all aqueous, Posted 6 years ago. Another source of variance stems from the shuttle of electrons across the mitochondrial membrane. What is substrate level. The thylakoid membrane corresponds to the inner membrane of the mitochondrion for transport of electrons and proton pumping (Figure \(\PageIndex{4}\)). Which of these statements is the correct explanation for this observation? Thus NADPH, ATP, and oxygen are the products of the first phase of photosynthesis called the light reactions. Instead, they are coupled together because one or more outputs from one stage functions as an input to another stage. The energetically "downhill" movement of electrons through the chain causes pumping of protons into the intermembrane space by the first, third, and fourth complexes. We also acknowledge previous National Science Foundation support under grant numbers 1246120, 1525057, and 1413739. Like the questions above. In eukaryotic cells, pyruvate is imported into the mitochondrial matrix for pyruvate oxidation. But technically there should be net two protons left in cytosol and that's where I am puzzled. d. NADH Adenosine 5'-triphosphate (ATP), the most abundant energy carrier molecule, has two high-energy phosphate . What affect would cyanide have on ATP synthesis? For instance, some intermediates from cellular respiration may be siphoned off by the cell and used in other biosynthetic pathways, reducing the number of ATP produced. Direct link to tmytltr's post if glycolysis requires AT, Posted 4 years ago. In biological systems, this reaction is vital for the cellular storage and transfer of free energy using energy carrier molecules.