{"id":305,"date":"2019-04-11T12:05:55","date_gmt":"2019-04-11T12:05:55","guid":{"rendered":"http:\/\/biocp04.epgpbooks.inflibnet.ac.in\/?post_type=chapter&#038;p=305"},"modified":"2019-04-15T07:21:34","modified_gmt":"2019-04-15T07:21:34","slug":"generation-of-atp","status":"publish","type":"chapter","link":"https:\/\/ebooks.inflibnet.ac.in\/biocp04\/chapter\/generation-of-atp\/","title":{"rendered":"Generation of ATP"},"content":{"raw":"<div><span style=\"float: right\"><a href=\"https:\/\/youtu.be\/o2_2Vjc8ozs\" target=\"_blank\" rel=\"noopener\"><img src=\"http:\/\/epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/2018\/11\/download.png\" alt=\"epgp books\" width=\"75px\" height=\"75px;\" \/><\/a>\r\n<\/span><\/div>\r\n<strong>\u00a0 \u00a0<\/strong>\r\n\r\n&nbsp;\r\n\r\n&nbsp;\r\n\r\n&nbsp;\r\n\r\n&nbsp;\r\n\r\n<strong>Biochemical mechanisms of generating ATP<\/strong>\r\n\r\n&nbsp;\r\n\r\nIn metabolisms, ATP is generated by two fundamental different biochemical mechanisms:\r\n<ol>\r\n \t<li>Substrate level phosphorylation, and<\/li>\r\n \t<li>Electron transport chain.<\/li>\r\n<\/ol>\r\n&nbsp;\r\n\r\n<strong><em>Substrate level phosphorylation<\/em><\/strong>\r\n<ul>\r\n \t<li style=\"text-align: justify\">In substrate level phosphorylation, ATP is formed from ADP by transfer of a high energy phosphate group from an intermediate of a fueling pathway.<\/li>\r\n \t<li style=\"text-align: justify\">The following reaction serve as an example<\/li>\r\n<\/ul>\r\n<img class=\"aligncenter size-full wp-image-306\" src=\"http:\/\/biocp04.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/215\/2019\/04\/1-150.png\" alt=\"\" width=\"319\" height=\"138\" \/>\r\n<ul>\r\n \t<li style=\"text-align: justify\">As a consequence of the removal of a molecule of water, the low- energy ester linkage of phosphate in 2- phosphoglyceric acid is converted to the high energy enol linkage in phosphoenol pyruvic acid.<\/li>\r\n<\/ul>\r\n<img class=\"aligncenter size-full wp-image-307\" src=\"http:\/\/biocp04.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/215\/2019\/04\/1-151.png\" alt=\"\" width=\"297\" height=\"219\" \/>\r\n<ul>\r\n \t<li style=\"text-align: justify\">This high- energy linked phosphate can then then be transferred to ADP, the consequence of which is generation of a molecule of ATP.<\/li>\r\n<\/ul>\r\n&nbsp;\r\n\r\n<strong><em>Generation of ATP by Electron Transport<\/em><\/strong>\r\n<ul>\r\n \t<li style=\"text-align: justify\">In a number of different mode of microbial metabolisms including respiration and photosynthesis, ATP is generated by transporting electron through the chain of carrier molecules with fixed orientation in a cell membrane.<\/li>\r\n<\/ul>\r\n<ul style=\"text-align: justify\">\r\n \t<li>Although the complexity and component of electron transport chain vary, they have a certain common features:<\/li>\r\n<\/ul>\r\n<ul>\r\n \t<li style=\"text-align: justify\">The component of chain are carrier molecules capable to undergoing revercible oxidation and reduction ; each member of chain is capable being reduced by reacting with the carrier molecules that precedes it and oxidized by the carrier that follows it.<\/li>\r\n<\/ul>\r\n<img class=\"aligncenter size-full wp-image-308\" src=\"http:\/\/biocp04.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/215\/2019\/04\/1-152.png\" alt=\"\" width=\"745\" height=\"236\" \/>\r\n<ul>\r\n \t<li style=\"text-align: justify\">In any specific example of an electron transport chain, certain members transport hydrogen atoms while other transport only electron.<\/li>\r\n<\/ul>\r\n<ul style=\"text-align: justify\">\r\n \t<li>The orientation of carrier in the cell membrane is such that hydrogen carriers transport in the direction toward the outside of the cell and electron carrier transport toward the inside.<\/li>\r\n<\/ul>\r\n<ul style=\"text-align: justify\">\r\n \t<li style=\"text-align: justify\">Thus, at each conjunction in the chain of a hydrogen carrier and an electron carrier, a proton is transported out of the cell.<\/li>\r\n<\/ul>\r\n<ul>\r\n \t<li style=\"text-align: justify\">The cell membrane is otherwise impermeable to proton ; as consequence electron transport traps a portion of the chemical energy released by the net reaction of the chain in the form of gradient across the membrane of proton and electric charge.<\/li>\r\n<\/ul>\r\n<ul>\r\n \t<li style=\"text-align: justify\">Such a gradient termed as proton motive force (\u0394p) is form of potential energy capable of doing work : it drives certain permease system that concentrate externally supplied substrate within the cell; it provides the energy for flagellar-mediated cell motility and its drives the energy requiring synthesis of ATP from ADP.<\/li>\r\n<\/ul>\r\n<ul>\r\n \t<li style=\"text-align: justify\">The synthesis of ATP at the expense of protonmotive force is catalyzed by complex membrane bound enzyme ,<span style=\"text-align: initial;font-size: 1em\"> ATP phosphohydrolase ( some time termed as ATP <\/span>ase<span style=\"text-align: initial;font-size: 1em\"> ) composed in all bacterial <\/span>studied ,<span style=\"text-align: initial;font-size: 1em\"> of two <\/span>multicomponant<span style=\"text-align: initial;font-size: 1em\"> protein BF0 and BF1.<\/span><\/li>\r\n<\/ul>\r\n<ul>\r\n \t<li style=\"text-align: justify\">The subunit composition and membrane insertion of BF0 and BF1 are shown in figure.<\/li>\r\n<\/ul>\r\n<ul style=\"text-align: justify\">\r\n \t<li>The \u03b1 and \u03b2 subunit of BF1are arranged alternately to form a hollow hexagon, the central hole of which contain the \u03b3 subunit associated with other subunit \u03b4 and \u03b5.<\/li>\r\n<\/ul>\r\n<ul style=\"text-align: justify\">\r\n \t<li>Thus BF1 probably has the subunit structure \u03b13\u03b23\u03b3\u03b4\u03b5 .<\/li>\r\n<\/ul>\r\n<ul>\r\n \t<li style=\"text-align: justify\">The \u03b1 and \u03b2 subunit form the catalytically active portion of structure ,the site where ATP is synthesized from ADP and inorganic phosphate ;the \u03b3,\u03b4 and \u03b5 subunit form a proton translocating stalk and gate that bring to the active site at the proper rate the proton that drive reaction.<\/li>\r\n<\/ul>\r\n<ul>\r\n \t<li style=\"text-align: justify\">The peptide form a proton channel through the membrane they are hihly hydrophobic accounting for their intra membrane location<\/li>\r\n<\/ul>\r\n<ul>\r\n \t<li style=\"text-align: justify\">ATP phosphohydrolase catalyzed a reversible reaction .ATP can be synthesize at a expense of proton motive force ,or in certain case a proton motive force can be established at the expense of intracellular ATP.<\/li>\r\n<\/ul>\r\n<img class=\"aligncenter size-full wp-image-311\" src=\"http:\/\/biocp04.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/215\/2019\/04\/1-153.png\" alt=\"\" width=\"567\" height=\"370\" \/>\r\n\r\nSchematic representation of the subunit composition and membrane insertation of\r\n\r\n&nbsp;\r\n\r\n&nbsp;\r\n\r\n<strong>Value of E<\/strong><strong>0<\/strong><strong>\u2019 for components in electron transport chains<\/strong>\r\n<ul>\r\n \t<li style=\"text-align: justify\">In order for an electron transport chain to function ,there must be a gradient of susceptibility to oxidation; i.e each component must be capable of being reduced by reduced form of previous component and oxidized by the oxidized form of the subsequent component in the chain.<\/li>\r\n<\/ul>\r\n<ul>\r\n \t<li style=\"text-align: justify\">The relative susceptibility of a substance to oxidation or reduction can be described quantitatively in terms of its electrode potential or reduction potential ;this<span style=\"text-align: initial;font-size: 1em\"> is the relative voltage required to remove an electron from H2. Thus standard reduction potential is that of <\/span>hydrogen<span style=\"text-align: initial;font-size: 1em\"> electrode<\/span><\/li>\r\n<\/ul>\r\n<img class=\"aligncenter size-full wp-image-312\" src=\"http:\/\/biocp04.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/215\/2019\/04\/1-154.png\" alt=\"\" width=\"170\" height=\"58\" \/>\r\n<ul>\r\n \t<li style=\"text-align: justify\">Which is assigned an arbitrary value of 0.0 volts under standard condition . At the pH 7.0,near which most biological reaction occurs, the potential of hydrogen electrode is -0.42 V.<\/li>\r\n<\/ul>\r\n<ul style=\"text-align: justify\">\r\n \t<li>The symbol E0\u2019 designates electrode potentials measured under these condition .<\/li>\r\n<\/ul>\r\n<ul>\r\n \t<li style=\"text-align: justify\">Knowing E0\u2019 value of two half reaction , the free energy changed of a coupled reaction can be calculated from the relationship<\/li>\r\n<\/ul>\r\n<img class=\"aligncenter size-full wp-image-313\" src=\"http:\/\/biocp04.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/215\/2019\/04\/1-155.png\" alt=\"\" width=\"219\" height=\"47\" \/>\r\n<ul>\r\n \t<li style=\"text-align: justify\">Where \u0394G\u20190 is the free energy change at pH 7.0 ;n is the number of electron transferred ;F is the faraday and \u0394E\u20190 is the algebraic difference between the potential of the two half reaction.<\/li>\r\n<\/ul>\r\n<ul>\r\n \t<li style=\"text-align: justify\">For example the reduction of oxygen by hydrogen as (H2 +1\/2 O2\u00e0H2O) can be divided in to two half reactions.<\/li>\r\n<\/ul>\r\n<img class=\"aligncenter size-full wp-image-314\" src=\"http:\/\/biocp04.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/215\/2019\/04\/1-156.png\" alt=\"\" width=\"337\" height=\"100\" \/>\r\n<ul>\r\n \t<li>The energy change can be calculated to be<\/li>\r\n<\/ul>\r\n<img class=\"aligncenter size-full wp-image-315\" src=\"http:\/\/biocp04.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/215\/2019\/04\/1-157.png\" alt=\"\" width=\"365\" height=\"104\" \/>\r\n<ul>\r\n \t<li style=\"text-align: justify\">For a typical biology oxidation , for example , the oxygen- linked oxidation of NADH (\u0394E\u20190 = -0.32V), the analogous calculation shows a free energy change of -52,400 cal, not significantly different from that for oxidation of hydrogen.<\/li>\r\n<\/ul>\r\n<ul style=\"text-align: justify\">\r\n \t<li>The carrier in an electron transport chain participate in a series of reaction of increasing \u0394E\u20190 values ,<span style=\"text-align: initial;font-size: 1em\"> between that of the primary electron donor and <\/span>terminal<span style=\"text-align: initial;font-size: 1em\"> electron acceptor.<\/span><\/li>\r\n<\/ul>\r\n<ul>\r\n \t<li style=\"text-align: justify\">The position on the E\u20190 scale of several typical electron carrier ,primary electron donor, and terminal electron acceptor are shown in figure.<\/li>\r\n<\/ul>\r\n<img class=\"aligncenter size-full wp-image-316\" src=\"http:\/\/biocp04.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/215\/2019\/04\/1-158.png\" alt=\"\" width=\"489\" height=\"459\" \/>\r\n\r\n&nbsp;\r\n\r\n<strong>The Componants of Electron Transport Chain<\/strong>\r\n<ul>\r\n \t<li style=\"text-align: justify\">The electron transport chain of aerobic chemoheterophs are the most thoroughly studied.<\/li>\r\n<\/ul>\r\n<ul style=\"text-align: justify\">\r\n \t<li>Those involved in the oxidation of organic compound always contain four different classes of molecules.<\/li>\r\n<\/ul>\r\n<ul style=\"text-align: justify\">\r\n \t<li>Two classes, the flavoprotein and quinines ,are hydrogen carrier; the others,the iron sulphur protein and cytochromes are electrone carriers.<\/li>\r\n<\/ul>\r\n<ul style=\"text-align: justify\">\r\n \t<li>Flavoprotein have a yellow-colored prosthetic group derived biosynthetically from riboflavin (vitamin B12).<\/li>\r\n<\/ul>\r\n<ul>\r\n \t<li style=\"text-align: justify\">The prosthetic group may be either flavin mononucleotide (FAD); both possess the same active site capable of undergoing reversible oxidation and reduction by donating or accepting two hydrogen atom respectively.<\/li>\r\n<\/ul>\r\n<img class=\"aligncenter size-full wp-image-317\" src=\"http:\/\/biocp04.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/215\/2019\/04\/1-159.png\" alt=\"\" width=\"432\" height=\"395\" \/>\r\n\r\n&nbsp;\r\n<ul>\r\n \t<li style=\"text-align: justify\">The flavo proteins are members of a large class and differ widely with respect to their E\u20190 values.<\/li>\r\n<\/ul>\r\n<ul style=\"text-align: justify\">\r\n \t<li>Some are active in the primary dehydrogenation of organic substrate (e.g succinate)\u00a0;other<span style=\"text-align: initial;font-size: 1em\"> participate as hydrogen carriers within an electron transport chain; and still <\/span>other<span style=\"text-align: initial;font-size: 1em\"> react directly with molecular oxygen with the formation of H2O2.<\/span><\/li>\r\n<\/ul>\r\n<ul style=\"text-align: justify\">\r\n \t<li>Most electron transport chain contain either ubiquinone , a substituted benzoquinone, or menaquinone , a substituted nepthaquinone.<\/li>\r\n<\/ul>\r\n<ul style=\"text-align: justify\">\r\n \t<li>The former occur most frequently in Garm negative bacteria and in the mitochondria of eukaryotes, and the latter most frequently in Gram positive bacteria.<\/li>\r\n<\/ul>\r\n<ul>\r\n \t<li style=\"text-align: justify\">A few facultative anaerobes, including, <em>E.Coli<\/em> ,contain both quinines but tend to use ubiquinone for aerobic respiration .<\/li>\r\n<\/ul>\r\n<ul>\r\n \t<li style=\"text-align: justify\">On reduction they accept two hydrogen atom to form the corresponding quinol.<\/li>\r\n<\/ul>\r\n<img class=\"aligncenter size-full wp-image-319\" src=\"http:\/\/biocp04.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/215\/2019\/04\/1-161.png\" alt=\"\" width=\"405\" height=\"234\" \/>\r\n\r\n&nbsp;\r\n\r\n<img class=\"aligncenter size-full wp-image-321\" src=\"http:\/\/biocp04.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/215\/2019\/04\/1-163.png\" alt=\"\" width=\"399\" height=\"239\" \/>\r\n\r\n&nbsp;\r\n\r\n<img class=\"aligncenter size-full wp-image-322\" src=\"http:\/\/biocp04.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/215\/2019\/04\/1-164.png\" alt=\"\" width=\"350\" height=\"236\" \/>\r\n<ul>\r\n \t<li style=\"text-align: justify\">The iron sulfur protein contain two, four or eight atoms of labile sulfur, so called because they are released as H2S by strong acids.<\/li>\r\n<\/ul>\r\n<ul>\r\n \t<li style=\"text-align: justify\">The iron atoms in 2 Fe-S protein are held in a lattice composed of four atoms of cysteine sulfur and the two labile sulfur atoms.<\/li>\r\n<\/ul>\r\n<ul style=\"text-align: justify\">\r\n \t<li>The iron atoms in the 4Fe-4S proteins interact with four labile sulfur atoms to form a cube that is held in place within the protein by four cysteine residue.<\/li>\r\n<\/ul>\r\n<ul style=\"text-align: justify\">\r\n \t<li style=\"text-align: justify\">The 8Fe-8S protein contain two active centers identical to those found in 4Fe-4S protein, thus enabling them to accept on reduction, two electrons while 2Fe-2S and 4Fe-4S protein can accept only one.<\/li>\r\n<\/ul>\r\n<ul style=\"text-align: justify\">\r\n \t<li>The cytochromes belong to the class of heme protein, a class that also includes hemoglobin and catlase.<\/li>\r\n<\/ul>\r\n<ul>\r\n \t<li style=\"text-align: justify\">All have one or more prosthetic groups derived from heme, a cyclic tetrapyrrole with an atom of iron chelated within the ring system.<\/li>\r\n<\/ul>\r\n<img class=\"aligncenter size-full wp-image-324\" src=\"http:\/\/biocp04.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/215\/2019\/04\/1-166.png\" alt=\"\" width=\"412\" height=\"326\" \/>\r\n<ul>\r\n \t<li>Electron transfer by the cytochromes involves a reversible oxidation of this iron atom<\/li>\r\n<\/ul>\r\n<img class=\"aligncenter size-full wp-image-325\" src=\"http:\/\/biocp04.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/215\/2019\/04\/1-167.png\" alt=\"\" width=\"163\" height=\"34\" \/>\r\n<ul>\r\n \t<li style=\"text-align: justify\">In an analogous way to the oxidation of an iron atom in the iron \u2013sulfur proteins.<\/li>\r\n<\/ul>\r\n<ul>\r\n \t<li style=\"text-align: justify\">The cytochromes have characteristic absorption band in the redused state that permit recognition of the several different members of the class, which are designated by terminal latter (e.g.,cytochrome c).<\/li>\r\n<\/ul>\r\n<img class=\"aligncenter size-full wp-image-326\" src=\"http:\/\/biocp04.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/215\/2019\/04\/1-168.png\" alt=\"\" width=\"433\" height=\"346\" \/>\r\n<ul>\r\n \t<li style=\"text-align: justify\">There are four types of heme prosthetic groups known (a,b,c,and d) that differ principally in the nature of the substituent group at the periphery of the heme.<\/li>\r\n<\/ul>\r\n<ul style=\"text-align: justify\">\r\n \t<li>Individual cytochromes contain one or more of these groups in various combinations.<\/li>\r\n<\/ul>\r\n<ul style=\"text-align: justify\">\r\n \t<li>The molecular weights and reduction potentials of cytochromes vary widely.<\/li>\r\n<\/ul>\r\n<ul style=\"text-align: justify\">\r\n \t<li>Cytochrome contentof bacteria is quite variable among species and environments.for example, an aerobically grown bacterium will have a different cytochrome composition from that of the same strain grown anaerobically or even grown with a restricted supply of oxygen.<\/li>\r\n<\/ul>\r\n<ul>\r\n \t<li style=\"text-align: justify\">The presence of a c- type cytochrome in a particular bacterium is correlated with the outcome of anempirical procedure , the oxidase test,whichhas considarble , diagnostic importance in identification of aerobic bacteria.<\/li>\r\n<\/ul>\r\n<ul style=\"text-align: justify\">\r\n \t<li>The test is performed by putting a small quantity of bacteria ona piece of filter paper soaked in a dye ; either dichlrophenol indophenols or N,N dimethyl-p-phenylene \u2013 diamine.<\/li>\r\n<\/ul>\r\n<ul>\r\n \t<li style=\"text-align: justify\">These dyes which are colorless in the reduced form by oxidase \u2013positive species(which lake a c-type cytochrome).<\/li>\r\n<\/ul>\r\n&nbsp;\r\n\r\n<strong>Arrangement of Electron Transport Chain in Membrane<\/strong>\r\n<ul>\r\n \t<li style=\"text-align: justify\">As stated bacteria are quite variable with respect to their cytochrome content ; they are also variable with respect to other constituents of electron transport chain.<\/li>\r\n<\/ul>\r\n<ul>\r\n \t<li style=\"text-align: justify\">A proposal for the aerobic respiratory chain in <em>Esherichia coli<\/em> is shown in figure.<\/li>\r\n<\/ul>\r\n<img class=\"aligncenter size-full wp-image-327\" src=\"http:\/\/biocp04.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/215\/2019\/04\/1-169.png\" alt=\"\" width=\"634\" height=\"254\" \/>\r\n\r\n&nbsp;\r\n<ul>\r\n \t<li style=\"text-align: justify\">NADH in the cytoplasm generated by a reaction in a fueling pathway transfers on the inner aspect of the membrane two hydrogens atoms toa flavoprotein embeded within the membrane.<\/li>\r\n<\/ul>\r\n<ul style=\"text-align: justify\">\r\n \t<li>On the outer aspect of the membrane the flavoprotein transfers two electrons to an iron sulfurprotein thereby releases them out side when it transfer twoelectron toa b-type cytochrome.<\/li>\r\n<\/ul>\r\n<ul style=\"text-align: justify\">\r\n \t<li>Finally, the cytochrome b transfer its electrons to another cytochrome that is termed a cytochrome oxidase because it has the capacity to transfer electrons to molecular oxygen in a reaction on the inner surface that has H2O as a product.<\/li>\r\n<\/ul>\r\n<ul>\r\n \t<li style=\"text-align: justify\">It will be noted that for each pair of electron transported through the chain four protons are pumped out of the cell, thus creating a proton motive force that can be used to do cellular work , for example ATP synthesis ,through the membrane bound ATP phosphohydrolase .<\/li>\r\n<\/ul>\r\n<ul style=\"text-align: justify\">\r\n \t<li style=\"text-align: justify\">It will also be noted that composition of the chain varies with the avilibility of oxygen.<\/li>\r\n<\/ul>\r\n<ul style=\"text-align: justify\">\r\n \t<li>When fully aerobic ,cytochrome b550 serve as terminal electron carrier and cytochrome o as the terminal oxidase.<\/li>\r\n<\/ul>\r\n<ul>\r\n \t<li style=\"text-align: justify\">When the supply of oxygen is limited cytochrome b558 and d play the corresponding roles.<\/li>\r\n<\/ul>\r\n&nbsp;\r\n<table>\r\n<tbody>\r\n<tr>\r\n<td><strong>you can view video on Generation of ATP<\/strong><\/td>\r\n<td><a href=\"https:\/\/youtu.be\/o2_2Vjc8ozs\" target=\"_blank\" rel=\"noopener\"><img class=\"alignnone wp-image-120\" src=\"http:\/\/epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/2018\/11\/download.png\" alt=\"\" width=\"36\" height=\"36\" \/><\/a><\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n&nbsp;\r\n<div class=\"textbox learning-objectives\">\r\n<h3>References<\/h3>\r\n<strong>Books<\/strong>\r\n<ul>\r\n \t<li style=\"text-align: justify\">Roger Y. Stanier, John L. Ingraham, Mark L. Wheelis, Page R. Painter. Genral Microbiology, Fifth edition 1995.<\/li>\r\n \t<li style=\"text-align: justify\">Clayton, R.K.,Photosynthesis: Physical mechanisms and chemical petterns.Cambridge: Cambridge university press, 1980.<\/li>\r\n \t<li style=\"text-align: justify\">Gottschalk,G.,Bacterial Metabolisms. New York, Heidelberg, and Berlin:springer-Verlag,1979.<\/li>\r\n \t<li style=\"text-align: justify\">Ingraham,JL.,O. Malloe and F.C Neidhardt, Growth of the bacterial cell.Sunderland,Mass.: Sinauer associates, INC.,1983.<\/li>\r\n \t<li style=\"text-align: justify\">Jones,C,W.,Bacterial respiration and photosynthesis Washington,D.C.:American society for microbiology,1982.<\/li>\r\n \t<li style=\"text-align: justify\">Lehninger,A.L., Principles of Biochemistry.New York:Worth publishers,1982.<\/li>\r\n \t<li style=\"text-align: justify\">Mandestam,J., and K.Mcquillen, Biochemistry of Bacterial growth. New York: John wiley,1982.<\/li>\r\n<\/ul>\r\n&nbsp;\r\n\r\n<strong>Web<\/strong>\r\n<ul>\r\n \t<li>http:\/\/www.angelfire.com\/ex\/firstperiodbiology\/<\/li>\r\n<\/ul>\r\n<\/div>\r\n&nbsp;\r\n\r\n&nbsp;\r\n\r\n&nbsp;","rendered":"<div><span style=\"float: right\"><a href=\"https:\/\/youtu.be\/o2_2Vjc8ozs\" target=\"_blank\" rel=\"noopener\"><img decoding=\"async\" src=\"http:\/\/epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/2018\/11\/download.png\" alt=\"epgp books\" width=\"75px\" height=\"75px;\" \/><\/a><br \/>\n<\/span><\/div>\n<p><strong>\u00a0 \u00a0<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p><strong>Biochemical mechanisms of generating ATP<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p>In metabolisms, ATP is generated by two fundamental different biochemical mechanisms:<\/p>\n<ol>\n<li>Substrate level phosphorylation, and<\/li>\n<li>Electron transport chain.<\/li>\n<\/ol>\n<p>&nbsp;<\/p>\n<p><strong><em>Substrate level phosphorylation<\/em><\/strong><\/p>\n<ul>\n<li style=\"text-align: justify\">In substrate level phosphorylation, ATP is formed from ADP by transfer of a high energy phosphate group from an intermediate of a fueling pathway.<\/li>\n<li style=\"text-align: justify\">The following reaction serve as an example<\/li>\n<\/ul>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-306\" src=\"http:\/\/biocp04.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/215\/2019\/04\/1-150.png\" alt=\"\" width=\"319\" height=\"138\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-150.png 319w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-150-300x130.png 300w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-150-65x28.png 65w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-150-225x97.png 225w\" sizes=\"auto, (max-width: 319px) 100vw, 319px\" \/><\/p>\n<ul>\n<li style=\"text-align: justify\">As a consequence of the removal of a molecule of water, the low- energy ester linkage of phosphate in 2- phosphoglyceric acid is converted to the high energy enol linkage in phosphoenol pyruvic acid.<\/li>\n<\/ul>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-307\" src=\"http:\/\/biocp04.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/215\/2019\/04\/1-151.png\" alt=\"\" width=\"297\" height=\"219\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-151.png 297w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-151-65x48.png 65w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-151-225x166.png 225w\" sizes=\"auto, (max-width: 297px) 100vw, 297px\" \/><\/p>\n<ul>\n<li style=\"text-align: justify\">This high- energy linked phosphate can then then be transferred to ADP, the consequence of which is generation of a molecule of ATP.<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<p><strong><em>Generation of ATP by Electron Transport<\/em><\/strong><\/p>\n<ul>\n<li style=\"text-align: justify\">In a number of different mode of microbial metabolisms including respiration and photosynthesis, ATP is generated by transporting electron through the chain of carrier molecules with fixed orientation in a cell membrane.<\/li>\n<\/ul>\n<ul style=\"text-align: justify\">\n<li>Although the complexity and component of electron transport chain vary, they have a certain common features:<\/li>\n<\/ul>\n<ul>\n<li style=\"text-align: justify\">The component of chain are carrier molecules capable to undergoing revercible oxidation and reduction ; each member of chain is capable being reduced by reacting with the carrier molecules that precedes it and oxidized by the carrier that follows it.<\/li>\n<\/ul>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-308\" src=\"http:\/\/biocp04.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/215\/2019\/04\/1-152.png\" alt=\"\" width=\"745\" height=\"236\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-152.png 745w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-152-300x95.png 300w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-152-65x21.png 65w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-152-225x71.png 225w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-152-350x111.png 350w\" sizes=\"auto, (max-width: 745px) 100vw, 745px\" \/><\/p>\n<ul>\n<li style=\"text-align: justify\">In any specific example of an electron transport chain, certain members transport hydrogen atoms while other transport only electron.<\/li>\n<\/ul>\n<ul style=\"text-align: justify\">\n<li>The orientation of carrier in the cell membrane is such that hydrogen carriers transport in the direction toward the outside of the cell and electron carrier transport toward the inside.<\/li>\n<\/ul>\n<ul style=\"text-align: justify\">\n<li style=\"text-align: justify\">Thus, at each conjunction in the chain of a hydrogen carrier and an electron carrier, a proton is transported out of the cell.<\/li>\n<\/ul>\n<ul>\n<li style=\"text-align: justify\">The cell membrane is otherwise impermeable to proton ; as consequence electron transport traps a portion of the chemical energy released by the net reaction of the chain in the form of gradient across the membrane of proton and electric charge.<\/li>\n<\/ul>\n<ul>\n<li style=\"text-align: justify\">Such a gradient termed as proton motive force (\u0394p) is form of potential energy capable of doing work : it drives certain permease system that concentrate externally supplied substrate within the cell; it provides the energy for flagellar-mediated cell motility and its drives the energy requiring synthesis of ATP from ADP.<\/li>\n<\/ul>\n<ul>\n<li style=\"text-align: justify\">The synthesis of ATP at the expense of protonmotive force is catalyzed by complex membrane bound enzyme ,<span style=\"text-align: initial;font-size: 1em\"> ATP phosphohydrolase ( some time termed as ATP <\/span>ase<span style=\"text-align: initial;font-size: 1em\"> ) composed in all bacterial <\/span>studied ,<span style=\"text-align: initial;font-size: 1em\"> of two <\/span>multicomponant<span style=\"text-align: initial;font-size: 1em\"> protein BF0 and BF1.<\/span><\/li>\n<\/ul>\n<ul>\n<li style=\"text-align: justify\">The subunit composition and membrane insertion of BF0 and BF1 are shown in figure.<\/li>\n<\/ul>\n<ul style=\"text-align: justify\">\n<li>The \u03b1 and \u03b2 subunit of BF1are arranged alternately to form a hollow hexagon, the central hole of which contain the \u03b3 subunit associated with other subunit \u03b4 and \u03b5.<\/li>\n<\/ul>\n<ul style=\"text-align: justify\">\n<li>Thus BF1 probably has the subunit structure \u03b13\u03b23\u03b3\u03b4\u03b5 .<\/li>\n<\/ul>\n<ul>\n<li style=\"text-align: justify\">The \u03b1 and \u03b2 subunit form the catalytically active portion of structure ,the site where ATP is synthesized from ADP and inorganic phosphate ;the \u03b3,\u03b4 and \u03b5 subunit form a proton translocating stalk and gate that bring to the active site at the proper rate the proton that drive reaction.<\/li>\n<\/ul>\n<ul>\n<li style=\"text-align: justify\">The peptide form a proton channel through the membrane they are hihly hydrophobic accounting for their intra membrane location<\/li>\n<\/ul>\n<ul>\n<li style=\"text-align: justify\">ATP phosphohydrolase catalyzed a reversible reaction .ATP can be synthesize at a expense of proton motive force ,or in certain case a proton motive force can be established at the expense of intracellular ATP.<\/li>\n<\/ul>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-311\" src=\"http:\/\/biocp04.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/215\/2019\/04\/1-153.png\" alt=\"\" width=\"567\" height=\"370\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-153.png 567w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-153-300x196.png 300w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-153-65x42.png 65w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-153-225x147.png 225w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-153-350x228.png 350w\" sizes=\"auto, (max-width: 567px) 100vw, 567px\" \/><\/p>\n<p>Schematic representation of the subunit composition and membrane insertation of<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p><strong>Value of E<\/strong><strong>0<\/strong><strong>\u2019 for components in electron transport chains<\/strong><\/p>\n<ul>\n<li style=\"text-align: justify\">In order for an electron transport chain to function ,there must be a gradient of susceptibility to oxidation; i.e each component must be capable of being reduced by reduced form of previous component and oxidized by the oxidized form of the subsequent component in the chain.<\/li>\n<\/ul>\n<ul>\n<li style=\"text-align: justify\">The relative susceptibility of a substance to oxidation or reduction can be described quantitatively in terms of its electrode potential or reduction potential ;this<span style=\"text-align: initial;font-size: 1em\"> is the relative voltage required to remove an electron from H2. Thus standard reduction potential is that of <\/span>hydrogen<span style=\"text-align: initial;font-size: 1em\"> electrode<\/span><\/li>\n<\/ul>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-312\" src=\"http:\/\/biocp04.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/215\/2019\/04\/1-154.png\" alt=\"\" width=\"170\" height=\"58\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-154.png 170w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-154-65x22.png 65w\" sizes=\"auto, (max-width: 170px) 100vw, 170px\" \/><\/p>\n<ul>\n<li style=\"text-align: justify\">Which is assigned an arbitrary value of 0.0 volts under standard condition . At the pH 7.0,near which most biological reaction occurs, the potential of hydrogen electrode is -0.42 V.<\/li>\n<\/ul>\n<ul style=\"text-align: justify\">\n<li>The symbol E0\u2019 designates electrode potentials measured under these condition .<\/li>\n<\/ul>\n<ul>\n<li style=\"text-align: justify\">Knowing E0\u2019 value of two half reaction , the free energy changed of a coupled reaction can be calculated from the relationship<\/li>\n<\/ul>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-313\" src=\"http:\/\/biocp04.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/215\/2019\/04\/1-155.png\" alt=\"\" width=\"219\" height=\"47\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-155.png 219w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-155-65x14.png 65w\" sizes=\"auto, (max-width: 219px) 100vw, 219px\" \/><\/p>\n<ul>\n<li style=\"text-align: justify\">Where \u0394G\u20190 is the free energy change at pH 7.0 ;n is the number of electron transferred ;F is the faraday and \u0394E\u20190 is the algebraic difference between the potential of the two half reaction.<\/li>\n<\/ul>\n<ul>\n<li style=\"text-align: justify\">For example the reduction of oxygen by hydrogen as (H2 +1\/2 O2\u00e0H2O) can be divided in to two half reactions.<\/li>\n<\/ul>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-314\" src=\"http:\/\/biocp04.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/215\/2019\/04\/1-156.png\" alt=\"\" width=\"337\" height=\"100\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-156.png 337w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-156-300x89.png 300w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-156-65x19.png 65w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-156-225x67.png 225w\" sizes=\"auto, (max-width: 337px) 100vw, 337px\" \/><\/p>\n<ul>\n<li>The energy change can be calculated to be<\/li>\n<\/ul>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-315\" src=\"http:\/\/biocp04.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/215\/2019\/04\/1-157.png\" alt=\"\" width=\"365\" height=\"104\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-157.png 365w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-157-300x85.png 300w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-157-65x19.png 65w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-157-225x64.png 225w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-157-350x100.png 350w\" sizes=\"auto, (max-width: 365px) 100vw, 365px\" \/><\/p>\n<ul>\n<li style=\"text-align: justify\">For a typical biology oxidation , for example , the oxygen- linked oxidation of NADH (\u0394E\u20190 = -0.32V), the analogous calculation shows a free energy change of -52,400 cal, not significantly different from that for oxidation of hydrogen.<\/li>\n<\/ul>\n<ul style=\"text-align: justify\">\n<li>The carrier in an electron transport chain participate in a series of reaction of increasing \u0394E\u20190 values ,<span style=\"text-align: initial;font-size: 1em\"> between that of the primary electron donor and <\/span>terminal<span style=\"text-align: initial;font-size: 1em\"> electron acceptor.<\/span><\/li>\n<\/ul>\n<ul>\n<li style=\"text-align: justify\">The position on the E\u20190 scale of several typical electron carrier ,primary electron donor, and terminal electron acceptor are shown in figure.<\/li>\n<\/ul>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-316\" src=\"http:\/\/biocp04.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/215\/2019\/04\/1-158.png\" alt=\"\" width=\"489\" height=\"459\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-158.png 489w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-158-300x282.png 300w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-158-65x61.png 65w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-158-225x211.png 225w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-158-350x329.png 350w\" sizes=\"auto, (max-width: 489px) 100vw, 489px\" \/><\/p>\n<p>&nbsp;<\/p>\n<p><strong>The Componants of Electron Transport Chain<\/strong><\/p>\n<ul>\n<li style=\"text-align: justify\">The electron transport chain of aerobic chemoheterophs are the most thoroughly studied.<\/li>\n<\/ul>\n<ul style=\"text-align: justify\">\n<li>Those involved in the oxidation of organic compound always contain four different classes of molecules.<\/li>\n<\/ul>\n<ul style=\"text-align: justify\">\n<li>Two classes, the flavoprotein and quinines ,are hydrogen carrier; the others,the iron sulphur protein and cytochromes are electrone carriers.<\/li>\n<\/ul>\n<ul style=\"text-align: justify\">\n<li>Flavoprotein have a yellow-colored prosthetic group derived biosynthetically from riboflavin (vitamin B12).<\/li>\n<\/ul>\n<ul>\n<li style=\"text-align: justify\">The prosthetic group may be either flavin mononucleotide (FAD); both possess the same active site capable of undergoing reversible oxidation and reduction by donating or accepting two hydrogen atom respectively.<\/li>\n<\/ul>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-317\" src=\"http:\/\/biocp04.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/215\/2019\/04\/1-159.png\" alt=\"\" width=\"432\" height=\"395\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-159.png 432w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-159-300x274.png 300w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-159-65x59.png 65w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-159-225x206.png 225w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-159-350x320.png 350w\" sizes=\"auto, (max-width: 432px) 100vw, 432px\" \/><\/p>\n<p>&nbsp;<\/p>\n<ul>\n<li style=\"text-align: justify\">The flavo proteins are members of a large class and differ widely with respect to their E\u20190 values.<\/li>\n<\/ul>\n<ul style=\"text-align: justify\">\n<li>Some are active in the primary dehydrogenation of organic substrate (e.g succinate)\u00a0;other<span style=\"text-align: initial;font-size: 1em\"> participate as hydrogen carriers within an electron transport chain; and still <\/span>other<span style=\"text-align: initial;font-size: 1em\"> react directly with molecular oxygen with the formation of H2O2.<\/span><\/li>\n<\/ul>\n<ul style=\"text-align: justify\">\n<li>Most electron transport chain contain either ubiquinone , a substituted benzoquinone, or menaquinone , a substituted nepthaquinone.<\/li>\n<\/ul>\n<ul style=\"text-align: justify\">\n<li>The former occur most frequently in Garm negative bacteria and in the mitochondria of eukaryotes, and the latter most frequently in Gram positive bacteria.<\/li>\n<\/ul>\n<ul>\n<li style=\"text-align: justify\">A few facultative anaerobes, including, <em>E.Coli<\/em> ,contain both quinines but tend to use ubiquinone for aerobic respiration .<\/li>\n<\/ul>\n<ul>\n<li style=\"text-align: justify\">On reduction they accept two hydrogen atom to form the corresponding quinol.<\/li>\n<\/ul>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-319\" src=\"http:\/\/biocp04.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/215\/2019\/04\/1-161.png\" alt=\"\" width=\"405\" height=\"234\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-161.png 405w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-161-300x173.png 300w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-161-65x38.png 65w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-161-225x130.png 225w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-161-350x202.png 350w\" sizes=\"auto, (max-width: 405px) 100vw, 405px\" \/><\/p>\n<p>&nbsp;<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-321\" src=\"http:\/\/biocp04.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/215\/2019\/04\/1-163.png\" alt=\"\" width=\"399\" height=\"239\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-163.png 399w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-163-300x180.png 300w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-163-65x39.png 65w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-163-225x135.png 225w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-163-350x210.png 350w\" sizes=\"auto, (max-width: 399px) 100vw, 399px\" \/><\/p>\n<p>&nbsp;<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-322\" src=\"http:\/\/biocp04.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/215\/2019\/04\/1-164.png\" alt=\"\" width=\"350\" height=\"236\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-164.png 350w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-164-300x202.png 300w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-164-65x44.png 65w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-164-225x152.png 225w\" sizes=\"auto, (max-width: 350px) 100vw, 350px\" \/><\/p>\n<ul>\n<li style=\"text-align: justify\">The iron sulfur protein contain two, four or eight atoms of labile sulfur, so called because they are released as H2S by strong acids.<\/li>\n<\/ul>\n<ul>\n<li style=\"text-align: justify\">The iron atoms in 2 Fe-S protein are held in a lattice composed of four atoms of cysteine sulfur and the two labile sulfur atoms.<\/li>\n<\/ul>\n<ul style=\"text-align: justify\">\n<li>The iron atoms in the 4Fe-4S proteins interact with four labile sulfur atoms to form a cube that is held in place within the protein by four cysteine residue.<\/li>\n<\/ul>\n<ul style=\"text-align: justify\">\n<li style=\"text-align: justify\">The 8Fe-8S protein contain two active centers identical to those found in 4Fe-4S protein, thus enabling them to accept on reduction, two electrons while 2Fe-2S and 4Fe-4S protein can accept only one.<\/li>\n<\/ul>\n<ul style=\"text-align: justify\">\n<li>The cytochromes belong to the class of heme protein, a class that also includes hemoglobin and catlase.<\/li>\n<\/ul>\n<ul>\n<li style=\"text-align: justify\">All have one or more prosthetic groups derived from heme, a cyclic tetrapyrrole with an atom of iron chelated within the ring system.<\/li>\n<\/ul>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-324\" src=\"http:\/\/biocp04.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/215\/2019\/04\/1-166.png\" alt=\"\" width=\"412\" height=\"326\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-166.png 412w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-166-300x237.png 300w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-166-65x51.png 65w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-166-225x178.png 225w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-166-350x277.png 350w\" sizes=\"auto, (max-width: 412px) 100vw, 412px\" \/><\/p>\n<ul>\n<li>Electron transfer by the cytochromes involves a reversible oxidation of this iron atom<\/li>\n<\/ul>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-325\" src=\"http:\/\/biocp04.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/215\/2019\/04\/1-167.png\" alt=\"\" width=\"163\" height=\"34\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-167.png 163w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-167-65x14.png 65w\" sizes=\"auto, (max-width: 163px) 100vw, 163px\" \/><\/p>\n<ul>\n<li style=\"text-align: justify\">In an analogous way to the oxidation of an iron atom in the iron \u2013sulfur proteins.<\/li>\n<\/ul>\n<ul>\n<li style=\"text-align: justify\">The cytochromes have characteristic absorption band in the redused state that permit recognition of the several different members of the class, which are designated by terminal latter (e.g.,cytochrome c).<\/li>\n<\/ul>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-326\" src=\"http:\/\/biocp04.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/215\/2019\/04\/1-168.png\" alt=\"\" width=\"433\" height=\"346\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-168.png 433w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-168-300x240.png 300w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-168-65x52.png 65w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-168-225x180.png 225w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-168-350x280.png 350w\" sizes=\"auto, (max-width: 433px) 100vw, 433px\" \/><\/p>\n<ul>\n<li style=\"text-align: justify\">There are four types of heme prosthetic groups known (a,b,c,and d) that differ principally in the nature of the substituent group at the periphery of the heme.<\/li>\n<\/ul>\n<ul style=\"text-align: justify\">\n<li>Individual cytochromes contain one or more of these groups in various combinations.<\/li>\n<\/ul>\n<ul style=\"text-align: justify\">\n<li>The molecular weights and reduction potentials of cytochromes vary widely.<\/li>\n<\/ul>\n<ul style=\"text-align: justify\">\n<li>Cytochrome contentof bacteria is quite variable among species and environments.for example, an aerobically grown bacterium will have a different cytochrome composition from that of the same strain grown anaerobically or even grown with a restricted supply of oxygen.<\/li>\n<\/ul>\n<ul>\n<li style=\"text-align: justify\">The presence of a c- type cytochrome in a particular bacterium is correlated with the outcome of anempirical procedure , the oxidase test,whichhas considarble , diagnostic importance in identification of aerobic bacteria.<\/li>\n<\/ul>\n<ul style=\"text-align: justify\">\n<li>The test is performed by putting a small quantity of bacteria ona piece of filter paper soaked in a dye ; either dichlrophenol indophenols or N,N dimethyl-p-phenylene \u2013 diamine.<\/li>\n<\/ul>\n<ul>\n<li style=\"text-align: justify\">These dyes which are colorless in the reduced form by oxidase \u2013positive species(which lake a c-type cytochrome).<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<p><strong>Arrangement of Electron Transport Chain in Membrane<\/strong><\/p>\n<ul>\n<li style=\"text-align: justify\">As stated bacteria are quite variable with respect to their cytochrome content ; they are also variable with respect to other constituents of electron transport chain.<\/li>\n<\/ul>\n<ul>\n<li style=\"text-align: justify\">A proposal for the aerobic respiratory chain in <em>Esherichia coli<\/em> is shown in figure.<\/li>\n<\/ul>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-327\" src=\"http:\/\/biocp04.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/215\/2019\/04\/1-169.png\" alt=\"\" width=\"634\" height=\"254\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-169.png 634w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-169-300x120.png 300w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-169-65x26.png 65w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-169-225x90.png 225w, https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-content\/uploads\/sites\/215\/2019\/04\/1-169-350x140.png 350w\" sizes=\"auto, (max-width: 634px) 100vw, 634px\" \/><\/p>\n<p>&nbsp;<\/p>\n<ul>\n<li style=\"text-align: justify\">NADH in the cytoplasm generated by a reaction in a fueling pathway transfers on the inner aspect of the membrane two hydrogens atoms toa flavoprotein embeded within the membrane.<\/li>\n<\/ul>\n<ul style=\"text-align: justify\">\n<li>On the outer aspect of the membrane the flavoprotein transfers two electrons to an iron sulfurprotein thereby releases them out side when it transfer twoelectron toa b-type cytochrome.<\/li>\n<\/ul>\n<ul style=\"text-align: justify\">\n<li>Finally, the cytochrome b transfer its electrons to another cytochrome that is termed a cytochrome oxidase because it has the capacity to transfer electrons to molecular oxygen in a reaction on the inner surface that has H2O as a product.<\/li>\n<\/ul>\n<ul>\n<li style=\"text-align: justify\">It will be noted that for each pair of electron transported through the chain four protons are pumped out of the cell, thus creating a proton motive force that can be used to do cellular work , for example ATP synthesis ,through the membrane bound ATP phosphohydrolase .<\/li>\n<\/ul>\n<ul style=\"text-align: justify\">\n<li style=\"text-align: justify\">It will also be noted that composition of the chain varies with the avilibility of oxygen.<\/li>\n<\/ul>\n<ul style=\"text-align: justify\">\n<li>When fully aerobic ,cytochrome b550 serve as terminal electron carrier and cytochrome o as the terminal oxidase.<\/li>\n<\/ul>\n<ul>\n<li style=\"text-align: justify\">When the supply of oxygen is limited cytochrome b558 and d play the corresponding roles.<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<table>\n<tbody>\n<tr>\n<td><strong>you can view video on Generation of ATP<\/strong><\/td>\n<td><a href=\"https:\/\/youtu.be\/o2_2Vjc8ozs\" target=\"_blank\" rel=\"noopener\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-120\" src=\"http:\/\/epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/2018\/11\/download.png\" alt=\"\" width=\"36\" height=\"36\" \/><\/a><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>&nbsp;<\/p>\n<div class=\"textbox learning-objectives\">\n<h3>References<\/h3>\n<p><strong>Books<\/strong><\/p>\n<ul>\n<li style=\"text-align: justify\">Roger Y. Stanier, John L. Ingraham, Mark L. Wheelis, Page R. Painter. Genral Microbiology, Fifth edition 1995.<\/li>\n<li style=\"text-align: justify\">Clayton, R.K.,Photosynthesis: Physical mechanisms and chemical petterns.Cambridge: Cambridge university press, 1980.<\/li>\n<li style=\"text-align: justify\">Gottschalk,G.,Bacterial Metabolisms. New York, Heidelberg, and Berlin:springer-Verlag,1979.<\/li>\n<li style=\"text-align: justify\">Ingraham,JL.,O. Malloe and F.C Neidhardt, Growth of the bacterial cell.Sunderland,Mass.: Sinauer associates, INC.,1983.<\/li>\n<li style=\"text-align: justify\">Jones,C,W.,Bacterial respiration and photosynthesis Washington,D.C.:American society for microbiology,1982.<\/li>\n<li style=\"text-align: justify\">Lehninger,A.L., Principles of Biochemistry.New York:Worth publishers,1982.<\/li>\n<li style=\"text-align: justify\">Mandestam,J., and K.Mcquillen, Biochemistry of Bacterial growth. New York: John wiley,1982.<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<p><strong>Web<\/strong><\/p>\n<ul>\n<li>http:\/\/www.angelfire.com\/ex\/firstperiodbiology\/<\/li>\n<\/ul>\n<\/div>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n","protected":false},"author":3,"menu_order":19,"template":"","meta":{"pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":["dr-ramesh-kothari"],"pb_section_license":""},"chapter-type":[],"contributor":[58],"license":[],"class_list":["post-305","chapter","type-chapter","status-publish","hentry","contributor-dr-ramesh-kothari"],"part":3,"_links":{"self":[{"href":"https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-json\/pressbooks\/v2\/chapters\/305","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-json\/wp\/v2\/users\/3"}],"version-history":[{"count":4,"href":"https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-json\/pressbooks\/v2\/chapters\/305\/revisions"}],"predecessor-version":[{"id":330,"href":"https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-json\/pressbooks\/v2\/chapters\/305\/revisions\/330"}],"part":[{"href":"https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-json\/pressbooks\/v2\/parts\/3"}],"metadata":[{"href":"https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-json\/pressbooks\/v2\/chapters\/305\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-json\/wp\/v2\/media?parent=305"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-json\/pressbooks\/v2\/chapter-type?post=305"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-json\/wp\/v2\/contributor?post=305"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/ebooks.inflibnet.ac.in\/biocp04\/wp-json\/wp\/v2\/license?post=305"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}