1fermentation

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Fermentation is made use of on a large scale in certain industries. Mici o-organisms like the different strains of bacteria

and yeat (fungus) are cultured in very large numbers and used for various purposes. 1. In bakeries - for preparingbread cakes and biscuits etc. . In bre!eries - for preparing !ine and other alcohols. ". In producing vinegar and in the

tanning and curing of leather.

In everyday life# fermentation is used !hile making $dosa$ and $bhatuia$ etc. %he kneaded flour or maida left for some

hours in !arm environment becomes some!hat spongy (leavening).

Fermentation products give a typical flavour and taste to these items.

II. Aerobic Respiration

&ll aerobic organisms obtain o'ygen from the atmosphere i.e. air and give out carbon dio'ide. %his e'change of gasesis only the mechanical part of aerobic respiration. &fter the absorbed o'ygen is transported to all parts of the body it isused to bring about complete breakdo!n of food molecules kno!n as cellular respiration.

rganisms differ in their mode of e'change of gases but not in their mode of cellular respiration.

%he overall euation for aerobic respiration can be !ritten as

C6H12O6+6O2->6CO2+6H2O+38ATP

&naerobic respiration is process of incomplete o'idation and produces less &%* !hereas aerobic is a process

of complete o'idation !ith the + production of more &%*.

Fermentation (anaerobic respiration) has industrial applications.

,ellular respiration is the process by !hich the chemical energy of food molecules is released and partially capturedin the form of &%*. ,arbohydrates# fats# and proteins can all be used as fuels in cellular respiration# but glucose is most

commonly used as an e'ample to e'amine the reactions and path!ays involved.

Cellular respirationdescribes the metabolic reactions and processes that take place in acellor across the cellmembrane to obtainbiochemical energyfrom fuel molecules and the release of the cells$ !aste products. nergy is

released by theo'idationof fuel molecules and is stored as high-energy carriers. %he reactions involved in respirationarecatabolic reactionsin metabolism.

Fuel molecules commonly used by cells in respiration include glucose#amino acidsand fatty acids# and a commono'idi/ing agent(electron acceptor) is molecularo'ygen(). %here are organisms# ho!ever# that can respire using

other organic moleculesas electron acceptors instead of o'ygen. rganisms that use o'ygen as a final electron acceptorin respiration are described as aerobic#!hile those that do not are referred to as anaerobic.

%he energy released in respiration is used to synthesi/e molecules that act as a chemical storage of this energy. ne ofthe most !idely used compounds in a cell isadenosine triphosphate(&%*) and its stored chemical energy can be used

for many processes reuiring energy# includingbiosynthesis#locomotionor transportation of molecules across cellmembranes.0ecause of its ubiuitous nature# &%* is also kno!n as the universal energy currency# since the amountof it in a cell indicates ho! much energy is available for energy-consuming processes.

Aenosine !"-trip#osp#ate(ATP) is a multifunctional nucleotidethat is most important as a molecularcurrency ofintracellular energytransfer.12In this role# &%* transports chemical energy !ithin cellsfor metabolism.It is producedas an energy source during the processes ofphotosynthesisandcellular respirationand consumed by many en/ymes
http://wiki/Cell_%2528biology%2529http://wiki/Cell_%2528biology%2529http://wiki/Cell_%2528biology%2529http://wiki/Energy_%2528biology%2529http://wiki/Energy_%2528biology%2529http://wiki/Oxidationhttp://wiki/Oxidationhttp://wiki/Oxidationhttp://wiki/Catabolismhttp://wiki/Catabolismhttp://wiki/Catabolismhttp://wiki/Glucosehttp://wiki/Glucosehttp://wiki/Amino_acidshttp://wiki/Amino_acidshttp://wiki/Amino_acidshttp://wiki/Fatty_acidshttp://wiki/Oxidizing_agenthttp://wiki/Electron_acceptorhttp://wiki/Oxygenhttp://wiki/Oxygenhttp://wiki/Organic_compoundhttp://wiki/Organic_compoundhttp://wiki/Aerobichttp://wiki/Aerobichttp://wiki/Anaerobic_organismhttp://wiki/Adenosine_triphosphatehttp://wiki/Adenosine_triphosphatehttp://wiki/Biosynthesishttp://wiki/Biosynthesishttp://wiki/Biosynthesishttp://wiki/Locomotionhttp://wiki/Locomotionhttp://wiki/Locomotionhttp://wiki/Cell_membranehttp://wiki/Cell_membranehttp://wiki/Cell_membranehttp://wiki/Nucleotidehttp://wiki/Nucleotidehttp://wiki/Moleculehttp://wiki/Moleculehttp://wiki/Energyhttp://wiki/Energyhttp://wiki/Cell_%2528biology%2529http://wiki/Cell_%2528biology%2529http://wiki/Metabolismhttp://wiki/Metabolismhttp://wiki/Photosynthesishttp://wiki/Photosynthesishttp://wiki/Cellular_respirationhttp://wiki/Cellular_respirationhttp://wiki/Enzymehttp://wiki/Enzymehttp://wiki/Cell_%2528biology%2529http://wiki/Energy_%2528biology%2529http://wiki/Oxidationhttp://wiki/Catabolismhttp://wiki/Glucosehttp://wiki/Amino_acidshttp://wiki/Fatty_acidshttp://wiki/Oxidizing_agenthttp://wiki/Electron_acceptorhttp://wiki/Oxygenhttp://wiki/Organic_compoundhttp://wiki/Aerobichttp://wiki/Anaerobic_organismhttp://wiki/Adenosine_triphosphatehttp://wiki/Biosynthesishttp://wiki/Locomotionhttp://wiki/Cell_membranehttp://wiki/Cell_membranehttp://wiki/Nucleotidehttp://wiki/Moleculehttp://wiki/Energyhttp://wiki/Cell_%2528biology%2529http://wiki/Metabolismhttp://wiki/Photosynthesishttp://wiki/Cellular_respirationhttp://wiki/Enzyme


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and a multitude of cellular processes includingbiosynthetic reactions#motilityandcell division.In signal transduction

path!ays# &%* is used as a substratebykinasesthatphosphorylateproteinsand lipids#as !ell as byadenylate cyclase#!hich uses &%* to produce the second messengermolecule cyclic &M*.

%he structure of this molecule consists of apurinebase (adenine) attached to the 1$ carbon atom of apentosesugar(ribose). %hree phosphate groups are attached at the 3$ carbon atom of the pentose sugar. &%* is also incorporated into

nucleic acidsbypolymerasesin the processes of45& replicationandtranscription.6hen &%* is used in 45&synthesis# the ribose sugar is first converted to deo'yribosebyribonucleotide reductase.&%* !as discovered in 177

by 8arl 9ohmann#2and !as proposed to be the main energy-transfer molecule in the cell byFrit/ &lbert 9ipmannin17:1."2

Aerobic respirationreuireso'ygenin order to generate energy (&%*). It is the preferred method ofpyruvate

breakdo!n from glycolysisand reuires that pyruvate enter themitochondrionto be fully o'idi/ed by the8rebs cycle.%he product of this process is energy in the form of &%* (&denosine %riphosphate)# bysubstrate-level phosphorylation#

5&4;andF&4;.

$i%pli&ie Reaction',


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()ternal respirationrefers to the e'change of gases bet!een the atmosphere and thepulmonary loopof circulation

including the lungs.'ygenis dra!n in through the respiratory tract# (nasal passages# into the pharyn'# to the trachea#the bronchial tubes to the alveoli sacs) and is then delivered to the blood !hich transports o'ygen throughout the body.From the lungs# o'ygen is transported across the thin membranes of the alveoli and the border of the capillary andattracted to the hemoglobinmolecule !ithin the red blood cell.

'ternal respiration is a passive process in that energy (&%*) is not e'pended by cells of the body as o'ygen passesfrom the air outside the nostrils to the red blood cell.4iffusionis the process utili/ed !hich means that the partial

pressure of o'ygen in the atmosphere helps provide the energyneeded for diffusion to occur. 'ternal respiration alsotransports carbon dio'idefrom the blood in the capillaries of the respiratory membrane through the capillary !all#through the alveoli !all# to the respiratory tract# and out into the surrounding air.

&%* is a chemical cataboli/ed (i.e.# broken do!n) from glucose and stored as energy in the mitochondria of cells throughout thebody. It is the necessary fuel for all body cellsE !ithout it# cells# and therefore the body# cannot operate. %he three main functionsof &%* in cellular function areD

1. %ransporting organic substancessuch as sodium# calcium# potassiumthrough the cell membrane.

. Gynthesi/ing chemical compounds# such as protein and cholesterol.

". Gupplying energy for mechanical !ork# such as muscle contraction.

nly a small amount of &%*about " ouncesis stored in the muscle cells at any given time. %his is enough energy to supportonly a fe! seconds of muscle contraction during intense activity. &s a result# &%* stores need to be constantly replenished in orderto keep the muscle cells fueled. ne of the !ays this occurs is by transforming &4* back into &%* in the muscle fiber. &s &%* is

used up and &4* stores accumulate# the bonds of another phosphate molecule# creatine phosphate (,*)# break. %his releasesenergy that is used to rebond &4* and * to form &%*. ;o!ever# there is very little ,* in muscle cells. %herefore# the &4*H,*reaction supplies only enough energy to support an additional " or : seconds of intense activity. 4uring periods of high intensitye'ercise# such as sprinting and !eight lifting# !hen short bursts of ma'imum output are called for# the total energy released from

the anaerobic &%*&4*,*&%* cycle is only capable of sustaining the cells energy needs for about @ seconds.. 0eyondthat# the body turns to other methods of generating &%* to keep the muscle fibers fueled.

4uring e'ercise periods lasting longer than < to @ seconds# muscle fibers cataboli/e stored glucosekno!n as glycogeninto &%*for fueling contractions. %his is done via t!o processesD Clycolysis# an anaerobic process# and o'idation# an aerobic process.

&denosine triphosphate (&%*) is often described as the body$s energy currencyenergy-producing metabolic A*Pis &or%e urin cellular respiration ,it# ener release b t#e breao,n o& lucose %olecules.Illustration by;ans + ,assidy. ,ourtesy of Cale Croup. reactions store theirenerin the form of &%*# !hich can then drive

energy-reuiring syntheses and other reactions any!here in the cell.

Gtructurally &%* consists of the purine base adenine (a comple'# double-ring%oleculecontaining five nitroen

ato%s) attached to the five-carbon sugar riboseE this combination is kno!n as adenosine. &ttaching a string of threeconnected phosphate groups to the ribose produces &%*. Gchematically# one may depict the structure of &%* as &d-

*h-*h-*h# !here &d is adenosine andP#is a phosphate group. If only t!o phosphate groups are attached# the resultingcompound isaenosine ip#osp#ate(&4*).

%he final step in almost all the body$s energy-producing mechanisms is attachment of the third phosphate group to&4*. %his ne! phosphate-phosphate bond# kno!n as a high-energy bond# effectively stores the energy that has been

produced. %he &%* then diffuses throughout the cell# eventually reaching sites !here energy is needed for such
http://wiki/Pulmonary_loophttp://wiki/Pulmonary_loophttp://wiki/Oxygenhttp://wiki/Oxygenhttp://wiki/Hemoglobinhttp://wiki/Hemoglobinhttp://wiki/Diffusionhttp://wiki/Diffusionhttp://wiki/Energyhttp://wiki/Energyhttp://wiki/Carbon_dioxidehttp://wiki/Carbon_dioxidehttp://pages/2491/Energy.htmlhttp://pages/2491/Energy.htmlhttp://pages/2491/Energy.htmlhttp://pages/1319/Cell.htmlhttp://pages/4414/Molecule.htmlhttp://pages/4414/Molecule.htmlhttp://pages/4414/Molecule.htmlhttp://pages/5127/pH.htmlhttp://pages/5127/pH.htmlhttp://pages/85/Adenosine-Diphosphate.htmlhttp://pages/85/Adenosine-Diphosphate.htmlhttp://wiki/Pulmonary_loophttp://wiki/Oxygenhttp://wiki/Hemoglobinhttp://wiki/Diffusionhttp://wiki/Energyhttp://wiki/Carbon_dioxidehttp://pages/2491/Energy.htmlhttp://pages/1319/Cell.htmlhttp://pages/4414/Molecule.htmlhttp://pages/5127/pH.htmlhttp://pages/85/Adenosine-Diphosphate.html


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processes asprotein synthesisor muscle cell contraction. &t these sites# en/%emechanisms couple the energy-reuiring processes to the breakdo!n of &%*$s high-energy bond. %his regenerates &4* and free phosphate# both of!hich diffuse back to the cell$s energy-producing sites and serve as ra! materials for production of more &%*.

%he &%*-&4* couple is thus analogous to a rechargeable storage batter# !ith energy production sites representingthe battery charger. &%* is the fully charged battery that can supply energy to a flashlight or transistor radio. &4* isthe used battery that is returned for charging.

&4* is not a fully drained battery# ho!ever. It still possesses one high-energy phosphate-phosphate bond. 6hen

energy is short and &%* is scarce# the second phosphate can be transferred from one &4* to another. %his creates ane! &%* molecule# along !ith one of adenosine monophosphate (&M*). Gince the fully drained &M* !ill probably

be broken do!n and disposed of# ho!ever# this mechanism represents an emergency response that is inhibited !hen&%* is plentiful.

&%* is also a building block in*0A snt#esis#!ith the adenosine and one phosphate being incorporated into thegro!ing heli'. (%he & in &%* is the same as in the &-,-C-% alphabet of DNA.) %his process differs from mostother &%*-using reactions# since it releases t!ophosphate groupsinitially still Joined# but soon separated. 6ith very

little pyrophosphate (*h-*h) available in the cell# the chance that it !ill break the 45& chain and again formthoughall en/yme reactions are theoretically reversibleis effectively infinitesimal. Gince breaking the 45& chain !ould

probably kill the cell# !hat at first might appear to be energy !astage turns out to be uite !orth!hile. %he cell alsoconverts &%* to &M* and pyrophosphate in a fe! other cases !here the reaction must al!ays go only in a single

direction.

Gee also Metabolism.
http://science.jrank.org/pages/86/Adenosine-Triphosphate.htmlhttp://science.jrank.org/pages/86/Adenosine-Triphosphate.htmlhttp://science.jrank.org/pages/86/Adenosine-Triphosphate.htmlhttp://pages/2541/Enzyme.htmlhttp://pages/779/Battery.htmlhttp://pages/2133/DNA-Synthesis.htmlhttp://pages/2133/DNA-Synthesis.htmlhttp://pages/2133/DNA-Synthesis.htmlhttp://science.jrank.org/pages/86/Adenosine-Triphosphate.htmlhttp://science.jrank.org/pages/86/Adenosine-Triphosphate.htmlhttp://pages/4253/Metabolism.htmlhttp://science.jrank.org/pages/86/Adenosine-Triphosphate.htmlhttp://pages/2541/Enzyme.htmlhttp://pages/779/Battery.htmlhttp://pages/2133/DNA-Synthesis.htmlhttp://science.jrank.org/pages/86/Adenosine-Triphosphate.htmlhttp://pages/4253/Metabolism.html

1fermentation

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