DOCSLIB.ORG

Ravenchapter07 8Th Edition F2012

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Ravenchapter07 8Th Edition F2012 How Cells Harvest Energy Chapter 9 We EAT sunlight energy trapped in arrangement of atoms CELLULAR RESPIRATION why do we need oxygen? energy Breathing by-product of photosynthesis? • Cellular Energy Harvest • Cellular Respiration – Glycolysis – Oxidation of Pyruvate – Krebs Cycle – Electron Transport Chain • Catabolism of Protein and Fat • Fermentation • Evolution of Metabolism burning fuel in the car •Organic compounds + O2 -> CO2 + H2O + Energy HEAT •Catabolic pathways release energy Autotrophs self feeders use photosynthesis (usually) to make their own food produce organic molecules from CO2 ALSO source for all nonautotrophic food! • Heterotrophs (us) consumers of biosphere – feed on • plants and others • dead organisms (feces, fallen leaves) – dependent on photoautotrophs for: – food – oxygen Cellular Respiration • Cells harvest energy • break chemical bonds and shift electrons OXIDATION OF GLUCOSE – GLUCOSE LOSES ELECTRONS (also protons ie hydrogen) – aerobic respiration - final electron acceptor is oxygen – anaerobic respiration - final electron acceptor is inorganic molecule (not oxygen) – fermentation - final electron acceptor is an organic molecule LIFE IS A LOT OF WORK! •Carbohydrates, fats, and proteins - all fuel •traditional - glucose •C6H12O6 + 6O2 -> 6CO2 + 6H2O + Energy (ATP + heat) •The catabolism of glucose is exergonic •delta G = 686 Kcal per mole of glucose. •positive or negative? •WASTE PRODUCTS HAVE LESS ENERGY • Remember Chemical reactions - exergonic or endergonic - based on free energy Do these products have more or less energy? • SPONTANEOUS (less energy, releases heat) Overall reaction: glucose + oxygen -> carbon dioxide + water + energy C6H12O6 + 6O2 6CO2 + 6H2O + energy how could this be measured in the lab? ATP • Adenosine Triphosphate • energy currency – drive movement – drive endergonic reactions • ATP Energy Currency : • adenosine triphosphate • nucleotide – nitrogenous base (adenine) – sugar (ribose) – three phosphate groups Figure 8.14a ATP •phosphate bonds –covalent, but weak - each has negative charge •repulsion contributes to instability – Negatives repel – Phosphates are negative – ATP (three phosphates), ADP (two phosphates) – Linking them requires overcoming repulsion Requires energy – ATP from ADP and a third phosphate requires energy (endergonic) – Releasing phosphate from ATP generates energy (exergonic) • bonds between phosphate groups broken by hydrolysis – Hydrolysis forms adenosine diphosphate – – [ATP -> ADP + Pi] – releases 7.3 Kcal of energy per mole of ATP – delta G is -13 kcal/mol Cell membrane •How IT WORKS IN extracellular Enzyme muscle cells Calcium ions –Calcium ions move to enzyme ATP binding Ca++ site Ca++ ATP –ATP splits -ADP and P phosphate ADP Ca++ P Cytosol –energy transfers phosphate intracellualr onto protein Ca++ P – –shape change drives calcium across membrane P biochemical pathways •ATP: Important Energy Storage Molecule energy stored as phosphate bond in ATP 3rd phosphate group energy released added to ADP when phosphate bond broken using energy from food p p p ATP energy energy IN OUT energy hill p p p p p p P + ADP P + ADP which is exergonic? enderogonic? but we only have about .5 - 3 min worth of ATP stored! Home runs and creatine? Creatine donates phosphate group! creatine – natural amino acid (not protein) C4H10N3O5P (liver, kidney) Lots in muscle, cardiovascular tissues increases phosphocreatine -> ATP “reservoir” for ATP production 1 g diet; 1 g synthesized high intensity exercise (baseball) • transfer of phosphate group from ATP phosphorylation Substrate level phosphorylation – changes shape - work (transport, mechanical, or chemical) – returns to alternate shape MUSCLE-RECYCLES 10 MILLION ATP/SEC Also oxidative phosphyloration • Uses proton gradient to produce ATP • What are protons? H + • Our cells do both redox reactions transfer electron(s) from one reactant to another oxidation-reduction reactions loss of electrons - oxidation (degrades, catabolic – ENERGY OUT) \addition of electrons – reduction (energy IN, anabolic) Hydrogen, electrons NAD is a Cofactor (co enzyme, organic) Na + Cl Na+ Cl- salt - redox reaction *Na is oxidized -the reducing agent *Cl is reduced – the oxidizing agent (Cl charge is reduced - drops from 0 to -1) electron donor (sodium) - reducing agent electron recipient (cloride) - oxidizing agent need both donor and acceptor Oxygen - potent oxidizing agent (it is reduced!) CH4 + 2O2 CO2 + 2H2O *CH4 is oxidized *O2 is reduced *oxidation often involves the loss of H Importance of electrons *key role in atom’s reactivity *CR - Transfer of e- through a series of steps releases energy the cell can use WHY SMALL STEPS? - HEAT cellular respiration – series of redox • glucose is oxidized, releasing energy (oxidation -loses electrons) C6H12O6 + 6O2 -> 6CO2 + 6H2O + energy (including heat) • oxygen is reduced (gains electrons) Hypoxia Shock Sepsis Altitude sickness Blood loss Systemic inflammation Path of e- in cellular respiration: food NADH e- transport chain oxygen Oxidation C6H12O6 + 6O2 6CO2 + 6H2O + energy Reduction * happens over a series of steps that involve special molecules called electron transporters • Electron Carrier Molecules Shuttle Electrons – Most important electron carrier is NAD+. COFACTOR NAD+ - oxidizing agent, accepts a hydrogen atom and TWO electrons, becoming NADH – NADH can carry electrons down energy hill on to another acceptor (also FAD/FADH) – Enzymes coordinate these transfers. - - - - NAD+ NADH NAD+ empty loaded empty + + H proton NAD + H oxidized - + - + NAD NAD H - - - + - H reduced + H Electron loss accompanied by protons (hydrogen ion) “dehydrogenation” 4 stages of cellular respiration 1.Glycolysis 2.Pryuvate Oxidation 3.Krebs cycle 4.Electron transport chain *net result of the 4 stages is about 36 ATP per glucose molecule Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Cytoplasm Glucose NADH Glycolysis ATP Pyruvate NADH Pyruvate CO Intermembrane oxidation 2 space Acetyl- CoA Mitochondrial matrix NADH CO2 Krebs cycle ATP FADH2 H2O ATP NAD+ and FAD - e Electron transport chain Inner mitochondrial membrane Mitochondrion •cellular respiration uses oxygen as a reactant to breakdown organic molecules •Most occurs in “matrix” of mitochondria •BUT 1st step (glycolysis) occurs in cytoplasm (before mitochondria) Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. OVERVIEW OF GLYCOLYSIS 1 2 3 6-carbon glucose (Starting material) 2 ATP P P P P 6-carbon sugar diphosphate 6-carbon sugar diphosphate SOME ENERGY OUT! P P P P ENERGY IN!!!!!! 3-carbon sugar 3-carbon sugar 3-carbon sugar 3-carbon sugar phosphate phosphate phosphate phosphate NADH NADH 2 ATP 2 ATP 3-carbon 3-carbon pyruvate pyruvate Priming reactions. Priming Cleavage reactions. Then, the Energy-harvesting reactions. reactions. Glycolysis begins with six-carbon molecule with two Finally, in a series of reactions, each the addition of energy. Two high- phosphates is split in two, forming of the two three-carbon sugar energy phosphates from two two three-carbon sugar phosphates is converted to molecules of ATP are added to the pyruvate. In the process, an energy- six-carbon molecule glucose, phosphates. rich hydrogen is harvested as producing a six-carbon molecule NADH, and two ATP molecules are with two phosphates. formed. glycolysis - steps 1. glucose (6 carbon-sugar) split into two, 3- carbon sugars 2. sugars are oxidized and rearranged to form 2 molecules of pyruvate. 3. Each step catalyzed by specific enzyme 4. steps divided into 2 phases: an energy investment phase and an energy payoff phase. *Most of the energy contained in glucose is still stored in pyruvate, which goes into the Krebs Cycle Glycolysis yields 2 ATP and 2 pyruvates, 2 NADH net yield of glycoloysis 2ATP, 2NADH, 2 pyruvates Can it end here? Copyright © The McGraw-Hill Companies, Inc. Permission equired for reproduction or display. With oxygen Without oxygen Pyruvate + H20 NAD CO2 NADH O2 NADH Acetaldehyde NADH Acetyl-CoA NAD+ + Lactate NAD Krebs cycle Ethanol • alcohol fermentation- pyruvate converted yeast to ethanol in 2 steps. in absence of oxygen (bread and wine) dump electrons from NADH onto acetaldehyde (converted from pyruvic acid by spewing off CO2)) reducing it to ethanol, and regenerating NAD+. • lactic acid fermentation in animals in absence of oxygen (muscle fatigue), pyruvate accepts electrons from NADH and regenerates NAD+, but is converted into lactic acid (muscle burn) • Muscle cells switch from AR to fermentation to generate ATP when O2 is scarce. • waste product, lactate -muscle fatigue, but ultimately converted back to pyruvate in the liver • used to make cheese and yogurt 4 stages of cellular respiration 1.Glycolysis 2.Pryuvate Oxidation 3.Krebs cycle 4.Electron transport chain *Pryuvate is “Fork in the road” pyruvate must be converted to Acetyl CoA Bridge between glycolysis and Krebs Cycle pyruvate enters mitochondria using transport protein in mitochondrial membrane, converted to Acetyl CoA (cofactor) - also releases NADH • Transition between Glycolysis and Krebs Cycle –In the presence of oxygen, each of the two pyruvic acids travels into the mitochondria. – Combine with coenzyme A to make acetyl CoA, one NADH, and CO2 –Next - Krebs cycle inner compartment of mitochondria Mitochondria • outer and inner phospholipid bilayer membrane • outer is smooth, inner membrane is folded crista (s) cristae(p) -matrix –SOLUTION - high concentration of enzymes REMEMBER mitochondrion? •For
Load more

Recommended publications
  • T E R R E N C E G . F R
    (3) How are the sites of protein import distributed over the surface of mitochondria and what is their T E R R E N C E G . F R E Y relationship to stable contact sites and crista junctions? We are studying the sites of protein import by microinjection of a protein construct into a giant Structure of Biological mutant of Neurospora. The construct contains an N- Macromolecules and Macromolecular terminal mitochondria target sequence, a stable Assemblies; Membrane Structure and folded protein domain to halt transport into Function; Electron Microscopy and mitochondria, and a colloidal gold particle to enable Image Processing visualization in electron micrographs. The sites of protein import will be mapped and correlated with Our research interests are the structural study the positions of stable contact sites and of crista of biological assemblies by application of biophysical junctions and biochemical methods. More specifically, we apply techniques of high resolution electron (4) What are the changes in mitochondria structure microscopy and digital image processing to study the during apoptosis? Mitochondria play a key role in structures of biological macromolecules, initiating the apoptosis program with the release of macromolecular assemblies, and whole organelles. cytochrome c into the cytosol. We are using Electron Currently we are studying the structure and function of tomography to study the structural changes in mitochondria using state of the art microscopic mitochondrial membranes in order to determine techniques, principally Electron Tomography. whether cytochrome c is released through specific Electron Tomography is a technique which calculates pores or through rupture of the outer membrane the three-dimensional structure from a series of following swelling of the matrix.
    [Show full text]
  • Cardiolipin and Mitochondrial Cristae Organization
    Biochimica et Biophysica Acta 1859 (2017) 1156–1163 Contents lists available at ScienceDirect Biochimica et Biophysica Acta journal homepage: www.elsevier.com/locate/bbamem Cardiolipin and mitochondrial cristae organization Nikita Ikon, Robert O. Ryan ⁎ Children's Hospital Oakland Research Institute, 5700 Martin Luther King Jr. Way, Oakland, CA 94609, United States article info abstract Article history: A fundamental question in cell biology, under investigation for over six decades, is the structural organization of Received 23 December 2016 mitochondrial cristae. Long known to harbor electron transport chain proteins, crista membrane integrity is key Received in revised form 3 March 2017 to establishment of the proton gradient that drives oxidative phosphorylation. Visualization of cristae morphol- Accepted 18 March 2017 ogy by electron microscopy/tomography has provided evidence that cristae are tube-like extensions of the mito- Available online 20 March 2017 chondrial inner membrane (IM) that project into the matrix space. Reconciling ultrastructural data with the lipid Keywords: composition of the IM provides support for a continuously curved cylindrical bilayer capped by a dome-shaped Cardiolipin tip. Strain imposed by the degree of curvature is relieved by an asymmetric distribution of phospholipids in Mitochondria monolayer leaflets that comprise cristae membranes. The signature mitochondrial lipid, cardiolipin (~18% of Cristae IM phospholipid mass), and phosphatidylethanolamine (34%) segregate to the negatively curved monolayer leaf- Membrane curvature let facing the crista lumen while the opposing, positively curved, matrix-facing monolayer leaflet contains pre- Non-bilayer lipid dominantly phosphatidylcholine. Associated with cristae are numerous proteins that function in distinctive Electron transport chain ways to establish and/or maintain their lipid repertoire and structural integrity.
    [Show full text]
  • Redalyc.Antioxidant Activity and Fermentative Metabolism in The
    Semina: Ciências Agrárias ISSN: 1676-546X [email protected] Universidade Estadual de Londrina Brasil Ferreira Larré, Cristina; Leivas Moraes, Caroline; Borella, Junior; do Amarante, Luciano; Deune, Sidnei; Peters, José Antonio Antioxidant activity and fermentative metabolism in the plant Erythrina crista-galli L. under flood conditions Semina: Ciências Agrárias, vol. 37, núm. 2, marzo-abril, 2016, pp. 567-580 Universidade Estadual de Londrina Londrina, Brasil Available in: http://www.redalyc.org/articulo.oa?id=445745368003 How to cite Complete issue Scientific Information System More information about this article Network of Scientific Journals from Latin America, the Caribbean, Spain and Portugal Journal's homepage in redalyc.org Non-profit academic project, developed under the open access initiative DOI: 10.5433/1679-0359.2016v37n2p567 Antioxidant activity and fermentative metabolism in the plant Erythrina crista-galli L. under flood conditions Atividade antioxidante e metabolismo fermentativo em plantas de Erythrina crista-galli sob alagamento Cristina Ferreira Larré1*; Caroline Leivas Moraes1; Junior Borella1; Luciano do Amarante2; Sidnei Deuner2; José Antonio Peters2 Abstract This study aimed to evaluate the mechanisms of flood tolerance of the root system of Erythrina crista- galli L. plants by measuring the activity of antioxidant enzymes and oxidative stress components in the leaves and roots. Additionally, the activity of fermentation enzymes in the roots was measured. The following two treatments were used: plants with flooded roots, which were maintained at a given water level above the soil surface, and non-flooded plants, which were used as the control. The measurements were performed at 10, 20, 30, 40, and 50 days after treatment.
    [Show full text]
  • BIOLOGY GLOSSARY (English – Chinese)
    BIOLOGY GLOSSARY (English – Chinese) A Site 核糖体 A 部位 abiotic factor 非生物因子[因素] absorption spectrum 吸收光谱 acclimatization 適應，馴化 accommodation 調節；視覺調節 acetylcholine 乙醛 acetyl CoA 乙酰輔酶 A，乙醯輔酶 A acid 酸 acid precipitation 酸性降水 acoelomate 无体腔[的] acquired immunity 后天性免疫 acrosome 顶体，顶体精子 actin 肌动蛋白 action potential 动作电位 activation energy 活化能 active site 活性部位/ 主动运输 active transport 主动运输 adenylyl cyclase 腺苷酸环化酶 adhesion 粘附 adrenal gland 肾上腺 aerobic 有氧的; 需氧的 agnathan 无颌类 agonistic behavior 格斗行为; 争斗行为 AIDS 愛滋病 aldehyde 醛 aldosterone 醛固酮 Alga 藻类 all-or-none event 全或无事件 allantois 尿囊 allele 等位基因 1 allopatric speciation 异地物种形成 allopolyploid 异源多倍体 allosteric site 变构部位 alpha helix α-螺旋 alternation of generations 世代交替 alveolus 牙槽,肺泡 amino acid 氨基酸 amino group 氨基 amino acyl-tRNA synthetase 氨基酰-tRNA 合成酶 aminocentesis 羊膜穿刺法 amnion 羊膜 amniote 羊膜 amniotic egg 羊膜卵 amphibia 两栖纲 amphipathic molecule • 两亲水脂分子 anaerobic 厌氧的 analogy 类比 androgens 雄激素 aneuploidy 非整倍性 angiosperm 被子植物 anion 阴离子；负离子 anterior 先前的; 前面的 anther 花药 antibiotic 抗生素 antibody 抗体 anticodon 反密码子 antidiuretic hormone (ADH) 抗利尿激素 antigen 抗原 aqueous solution 水溶液 archaebacteria 古细菌 archenteron 原肠 artery 动脉 2 arteriole 小动脉 arteriosclerosis 动脉硬化 asexual reproduction 无性生殖 assortive mating 同型交配 atomic number 原子序数 atomic weight 原子量 ATP (adenosine triphosphate) 三磷酸腺苷 ATP synthase • ATP 合成酶 atrioventricular valve 房室瓣 atrium 心房 autoimmune disease 自身免疫病 autonomic nervous system 自主神经系统 autopolyploid 同源多倍体 autosome 常染色体 autotroph 自养生物 axon 轴突 B cell B 细胞 bacteria (plural) bacterium (single) 细菌 bark 树皮 Barr body 性染色质,巴尔氏小体
    [Show full text]
  • Multicolor 3D MINFLUX Nanoscopy of Mitochondrial MICOS Proteins
    Multicolor 3D MINFLUX nanoscopy of mitochondrial MICOS proteins Jasmin K. Papea,1, Till Stephana,b,1, Francisco Balzarottia,2, Rebecca Büchnera, Felix Langea,b, Dietmar Riedelc, Stefan Jakobsa,b,3, and Stefan W. Hella,d,3 aDepartment of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany; bClinic of Neurology, University Medical Center Göttingen, 37075 Göttingen, Germany; cLaboratory of Electron Microscopy, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany; and dDepartment of Optical Nanoscopy, Max Planck Institute for Medical Research, 69120 Heidelberg, Germany Contributed by Stefan W. Hell, June 23, 2020 (sent for review May 13, 2020; reviewed by Clemens F. Kaminski and Valentin Nägerl) The mitochondrial contact site and cristae organizing system (MICOS) subunits (8, 9). In humans, MICOS consists of at least seven dif- is a multisubunit protein complex that is essential for the proper ferent subunits, which are part of two MICOS subcomplexes, architecture of the mitochondrial inner membrane. MICOS plays a key namely, the Mic60 and Mic10 subcomplexes. The Mic60 subcomplex role in establishing and maintaining crista junctions, tubular or slit-like encompasses Mic60, Mic25, and Mic19, whereas the Mic10 structures that connect the cristae membrane with the inner boundary subcomplex consists of Mic10, Mic13, Mic26, and Mic27 (10–12). membrane, thereby ensuring a contiguous inner membrane. MICOS is Immunogold electron microscopy demonstrated that Mic60 is enriched at crista junctions, but the detailed distribution of its subunits highly enriched at crista junctions (5, 13). Two-dimensional (2D) around crista junctions is unclear because such small length scales are stimulated emission depletion (STED) nanoscopy suggested that inaccessible with established fluorescence microscopy.
    [Show full text]
  • Full-Text.Pdf
    Cutting Edge: Glycolytic Metabolism and Mitochondrial Metabolism Are Uncoupled in Ag-Activated CD8+ Recent Thymic Emigrants This information is current as of September 25, 2021. Cody A. Cunningham, Suzanne Hoppins and Pamela J. Fink J Immunol published online 1 August 2018 http://www.jimmunol.org/content/early/2018/07/31/jimmun ol.1800705 Downloaded from Supplementary http://www.jimmunol.org/content/suppl/2018/07/31/jimmunol.180070 Material 5.DCSupplemental http://www.jimmunol.org/ Why The JI? Submit online. • Rapid Reviews! 30 days* from submission to initial decision • No Triage! Every submission reviewed by practicing scientists • Fast Publication! 4 weeks from acceptance to publication by guest on September 25, 2021 *average Subscription Information about subscribing to The Journal of Immunology is online at: http://jimmunol.org/subscription Permissions Submit copyright permission requests at: http://www.aai.org/About/Publications/JI/copyright.html Email Alerts Receive free email-alerts when new articles cite this article. Sign up at: http://jimmunol.org/alerts The Journal of Immunology is published twice each month by The American Association of Immunologists, Inc., 1451 Rockville Pike, Suite 650, Rockville, MD 20852 Copyright © 2018 by The American Association of Immunologists, Inc. All rights reserved. Print ISSN: 0022-1767 Online ISSN: 1550-6606. Published August 1, 2018, doi:10.4049/jimmunol.1800705 Cutting Edge: Glycolytic Metabolism and Mitochondrial Metabolism Are Uncoupled in Ag-Activated CD8+ Recent Thymic Emigrants Cody A. Cunningham,*,1 Suzanne Hoppins,† and Pamela J. Fink* Recent thymic emigrants (RTEs) are peripheral T cells imparts lasting functional differences that distinguish that have most recently completed selection and thymic RTE-derived memory cells from mature T cell–derived memory egress and constitute a population that is phenotypi- cells (8).
    [Show full text]
  • A Thermodynamic Model Describing the Nature of the Crista Junction; a Structural Motif in the Mitochondrion
    Working Title: A thermodynamic model describing the nature of the crista junction; a structural motif in the mitochondrion. Christian Renken†*, Gino Siragusa‡, Guy Perkins§, Lance Washington†, Jim Nulton‡, Peter Salamon‡, and Terrence G. Frey†§. †Department of Biology San Diego State University, San Diego, CA 92185 ‡Department of Physics San Diego State University, San Diego, CA 92185 §National Center for Microscopy and Imaging Research, University of California San Diego, La Jolla, CA Key Words: electron tomography, membrane topology, mitochondria, modeling, spontaneous curvature. *To whom correspondence should be addressed: Christian Renken Wadsworth Center, NY State Dept. Health Empire State Plaza, P.O.Box 509 Albany, NY 12201-0509 Tel: 518-473-0202 Fax: 518-474-7992 Email:[email protected] Abstract: The use of electron tomography has allowed the three-dimensional membrane topography of the mitochondrion to be better understood. The most striking feature of this topology is the crista junction, a structure that may serve to divide functionally the inner-membrane and inter-membrane spaces. In situ these junctions seem to have a preferred size and shape independent of the source of the mitochondrion with few exceptions. When mitochondria are isolated and have a condensed matrix the crista junctions enlarge and become non-discrete. Upon permeation of the inner membrane and subsequent swelling of the matrix space, the uniform circular nature of the crista junction reappears. We examine the distribution of shapes and sizes of crista junctions and suggest a thermodynamic model that explains the distribution based on current theories of bilayer membrane shapes. The theory of spontaneous curvature shows the circular junction to be a thermodynamically stable structure whose size and shape is influenced by the relative volume of the matrix.
    [Show full text]
  • Lateral Ph Gradient Between OXPHOS Complex IV and F0F1 ATP-Synthase in Folded Mitochondrial Membranes
    ARTICLE Received 29 Sep 2013 | Accepted 13 Dec 2013 | Published 29 Jan 2014 DOI: 10.1038/ncomms4103 Lateral pH gradient between OXPHOS complex IV and F0F1 ATP-synthase in folded mitochondrial membranes Bettina Rieger1, Wolfgang Junge2 & Karin B. Busch1 Ion-driven ATP synthesis by rotary F0F1 ATP-synthase powers aerobic life. Since Mitchell’s seminal hypothesis, this synthesis has been discussed in terms of the proton-motive force between two bulk phases, each in equilibrium. In active mitochondria, a steady proton flow cycles between pumps and the distant ATP synthase. Here we determine the lateral pH profile along the p-side of cristae in situ by attaching a ratiometric fluorescent pH-sensitive GFP variant to OXPHOS complex IV, a proton pump, and the dimeric F0F1 ATP-synthase, a proton consumer. In respiring HeLa cells, we observe that the local pH at F0F1 dimers is 0.3 units less acidic than that at complex IV. This finding is consistent with the calculated pH profile for steady proton diffusion from CIV to F0F1. The observed lateral variation in the proton-motive force necessitates a modification to Peter Mitchell’s chemiosmotic proposal. The experimental technique can be extended to other pH-dependent reactions in membrane microcompartments. 1 Division of Mitochondrial Dynamics, Fachbereich Biologie/Chemie, Universita¨t Osnabru¨ck, D-49076 Osnabru¨ck, Germany. 2 Niedersachsen-Professur fu¨r Biophysik, Fachbereich Biologie/Chemie, Universita¨t Osnabru¨ck, D-49076 Osnabru¨ck, Germany. Correspondence and requests for materials should be addressed to K.B.B. (email: [email protected]). NATURE COMMUNICATIONS | 5:3103 | DOI: 10.1038/ncomms4103 | www.nature.com/naturecommunications 1 & 2014 Macmillan Publishers Limited.
    [Show full text]
  • Helical Arrays of U-Shaped ATP Synthase Dimers Form Tubular Cristae in Ciliate Mitochondria
    Helical arrays of U-shaped ATP synthase dimers form tubular cristae in ciliate mitochondria Alexander W. Mühleipa, Friederike Joosa, Christoph Wiggeb,c,1, Achilleas S. Frangakisb,c, Werner Kühlbrandta,2, and Karen M. Daviesa,2,3,4 aDepartment of Structural Biology, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany; bBuchmann Institute for Molecular Life Sciences, Goethe-University Frankfurt, 60438 Frankfurt am Main, Germany; and cInstitute for Biophysics, Goethe-University Frankfurt, 60438 Frankfurt am Main, Germany Edited by Richard Henderson, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom, and approved May 23, 2016 (received for review December 23, 2015) F1Fo-ATP synthases are universal energy-converting membrane pro- is unclear, however rows of ATP synthase dimers have been pro- tein complexes that synthesize ATP from ADP and inorganic phos- posed to promote the formation of lamellar cristae in yeast (20, 26). phate. In mitochondria of yeast and mammals, the ATP synthase So far, all rows of ATP synthase dimers observed by electron forms V-shaped dimers, which assemble into rows along the highly cryotomography have been more or less straight (19–22, 27). curved ridges of lamellar cristae. Using electron cryotomography and However, an earlier deep-etch freeze-fracture study of mitochon- subtomogram averaging, we have determined the in situ structure dria from the ciliate Paramecium multimicronucleatum revealed and organization of the mitochondrial ATP synthase dimer of the double rows of interdigitating 10-nm particles on helical tubular ciliate Paramecium tetraurelia. The ATP synthase forms U-shaped cristae (28). These particles were interpreted as ATP synthases, dimers with parallel monomers.
    [Show full text]
  • Cristae Formation—Linking Ultrastructure and Function of Mitochondria
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Elsevier - Publisher Connector Biochimica et Biophysica Acta 1793 (2009) 5–19 Contents lists available at ScienceDirect Biochimica et Biophysica Acta journal homepage: www.elsevier.com/locate/bbamcr Review Cristae formation—linking ultrastructure and function of mitochondria Michael Zick a, Regina Rabl a, Andreas S. Reichert b,⁎ a Adolf-Butenandt-Institut für Physiologische Chemie, Ludwig-Maximilians-Universität München, Butenandtstr. 5, 81377 München, Germany b CEF Makromolekulare Komplexe, Mitochondriale Biologie, Fachbereich Medizin, Goethe-Universität Frankfurt am Main, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany article info abstract Article history: Mitochondria are double-membrane enclosed eukaryotic organelles with a central role in numerous cellular Received 4 March 2008 functions. The ultrastructure of mitochondria varies considerably between tissues, organisms, and the Received in revised form 5 June 2008 physiological state of cells. Alterations and remodeling of inner membrane structures are evident in Accepted 12 June 2008 numerous human disorders and during apoptosis. The inner membrane is composed of two subcompart- Available online 20 June 2008 ments, the cristae membrane and the inner boundary membrane. Recent advances in electron tomography led to the current view that these membrane domains are connected by rather small tubular structures, Keywords: Mitochondria termed crista junctions. They have been proposed to regulate the dynamic distribution of proteins and lipids Cristae formation as well as of soluble metabolites between individual mitochondrial subcompartments. One example is the Crista junction release of cytochrome c upon induction of apoptosis. However, only little is known on the molecular Electron tomography mechanisms mediating the formation and maintenance of cristae and crista junctions.
    [Show full text]
  • Intro Bio Lecture 9
    Characteristics of metabolic pathways Aside from its role in energy metabolism: Glycolysis is a good example of a metabolic pathway. Two common characteristics of a metabolic pathway, in general: 1) Each step = a small chemically reasonable change 2) The overall ∆Go is substantial and negative. 1 Energy yield But all this spewing of lactate turns out to be wasteful. Using oxygen as an oxidizing agent glucose could be completely oxidized, to: … CO2 That is, burned. How much energy released then? Glucose + 6 O2 6 CO2 + 6 H2O ∆Go = -686 kcal/mole ! Compared to -45 for glucose 2 lactates (both w/o ATP production considered) Complete oxidation of glucose, Much more ATP But nature’s solution is a bit complicated. The fate of pyruvate is now different 2 From glycolysis: acetyl-CoA 3 pyruvic acid Scores: per glucose 2 NADH 2 ATP pyruvic acid 2 NADH 2 CO2 citric acid oxaloacetic acid Krebs cycle Citric acid cycle isocitric acid malic acid Tricarboxylic acid cycle TCA cycle fumaric acid α keto glutaric acid succinic Handout 9A acid 3 Acetyl-OCoA O|| CH3 –C –OH + co-enzyme A acetyl~CoA acetic acid (acetate) coA acetate group pantothenic acid (vitamin B5) 4 Per glucose FromB glycolysis: acetyl-coA pyruvate Input 2 oxaloacetates 2 NADH 2 ATP pyruvic acid 2 NADH 2 NADH 2 CO 2 NADH 2 2 CO2 citric acid 2 CO2 oxaloacetic acid 6 CO2 Krebs Cycle isocitric acid malic acid fumaric acid α keto glutaric acid succinic acid 5 GTP is energetically equivalent to ATP GTP + ADP GDP + ATP ΔGo = ~0 G= guanine (instead of adenine in ATP) 6 acetyl-CoA B Per 7glucose 2 oxaloacetate 2 NADH 2 ATP pyruvic acid 2 NADH 2 NADH 2 NADH 2 FADH2 citric acid 2 NADH oxaloacetic acid 2 CO2 2 CO2 Krebs cycle 2 CO2 isocitric acid malic acid 6 CO2 fumaric acid α keto glutaric acid succinic acid 7 FAD = flavin adenine dinucleotide Business end (flavin) ~ Vitamin B2 ribose adenine - ribose FAD + 2H.
    [Show full text]
  • Fatty Acid Catabolism (Oxidation)
    The electron transport chain H+ ions (protons) are pumped out as the electrons are transferred (outside) FADH2 FAD Complex: I II III IV Nelson and Cox, Principles of Biochemistry 1 Close-up of crista, showing proton flow the inside 1 pair of NADH electrons going down ATP the ETC ~10 H+’s pumped out synthase crista + ADP + + + + ATP + + + + + + + + the outside 2 Close-up of crista, showing proton flow ATP synthase the inside crista + ADP + + Pi + + + + ATP + + + + the + + outside ~10 H+’s ~10 H+’s 3 ATP 3 ADP + 3 Pi 1 NAD + 1 H2O 1 NADH2 + ½ O2 3 Close-up of crista, showing proton flow ATP synthase ? the inside ? crista + ADP + + + + + ATP + + What about E. coli? Its cell membrane houses all components 4 ATP synthase (or the F0F1 complex) MW = ~500,000 the inside H+ outside a c F0 ε γ b α β F δ 1 the outside inside Gamma subunit acts as a cam Gamma subunit is inserted inside the αβs 5 Cryo electron microscopy Math, computational algorithms Joachim Frank 2017 Nobel Prize in Chemistry* Rubinstein JL, Walker JE, Henderson R. Structure of the mitochondrial ATP synthase by *Dept. of Biological Sciences electron cryomicroscopy. The EMBO Journal. Columbia University 2003;22(23):6182-6192. 6 7 not top view ATP synthase β fixed fixed α α inside β β α http://employees.csbsju.edu/hjakubowski/classe s/ch331/oxphos/olcouplingoxphos.html a subunit c subunit fixed not outside fixed Flow of protons turns the C-subunit wheel. C-subunits turn the gamma cam. 8 Movie link 9 ATP synthase action Start here (top view) alpha+beta ADP Pi + + +H +H +H+ gamma Three conformational states of the α-β subunit: L, T, and O 10 Outside Mitochondria Inside 11 Is it really a motor? Actin molecules Attach a big arm Detach the C-subunits 10 nm 10 total length =~1 micron 12 Testing the ATP synthase motor model by running it in reverse (no H+ gradient, add ATP) actin filament Actin labeled Actin is a muscle by tagging it with protein polymer fluorescent molecules Attached to the gamma subunit Add lots of ATP His-tag Junge et al.
    [Show full text]