It StARtS It cell splits to bee ter just forty-seven doublings, you en trillion(10,000,000,000,000,000) cells in your body and are ready t forth as a human being.

        1And every one of tly o do to preserve and nurture you from t of ception to your last breath.

        You s from your cells. t you te geic code—truanual for your body—so itkno only o do its job but every oto remind a cell to keep an eye on its adenosiripe levels or to find a place fortra squirt of folic acid t’s just uedly turned up. It    for you, andmillions more things besides.

        Every cell in nature is a t are far beyond ts ofy. to build t basic yeast cell, for example, you urize about ts as are found in a Boeing 777 jetliner andfit to a sp five mis across; to persuade tspo reproduce.

        But yeast cells are as not just more variedand plicated, but vastly more fasating because of teras.

        Your cells are a try of ten trillion citizens, eaced in some intensivelyspecific o your overall    a t do for you. tyou feel pleasure and form ts. to stand and stretc, tract trients, distribute tes—all t in junior    to make you plad reer you fet to eat again. tlypurring. to your defeantyou are teatingly die for you—billions of t on all your years    us take a moment nard tion they deserve.

        e uand a little of    ormanufacture insulin age in many of ts necessary to maintain a plicatedentity like yourself—but only a little. You    least 200,000 different types of protein1Actually, quite a lot of cells are lost in t, so t a guess. Depending oen trillion (or quadrillion) is from Margulis and Sagan, 1986.

        lab aand    2 pert oft t more like 50 pert; it depends, apparently, on and.”)Surprises at turn up all time. In nature, nitric oxide is a formidabletoxin and a on po of air pollution. So stists urally a little surpriseded manner ins purpose    first a mystery, but tists began to find it all over trolling ttag cers andoting ting in penile eres. It alsoexplained    pain kno is verted into nitric oxide in tream, relaxing to floance    from extraneous toxin to ubiquitous elixir.

        You    possess    “some    feypes of cell, acc to t    de Duve, and ts    stretco several feet to tiny, disc-so tocells t o give us vision. tuously    t of ception, s an egg eigimes bigger t (ionof male quest into perspective). On average,    tymis    is about to be seenbut roomy enougo ed structures like mitoc literal ’s a someion to reflect t every inc you are lugging around about five pounds of deadskin, of s are slougy stern very largely in old skin.

        Most living cells seldom last more t tableexceptions. Liver cells    survive for years, ts    as long as you do. You are issued a    birt is all you are ever going to get. It imated t you lose fiveo do t a momentto e. t ts of your brain cells are stantlyrene, as    of tually likely to be more ta mo t a si of any of us—not somucray molecule—t    of us nine years ago. It may not feel like it, but at ters.

        t person to describe a cell     enteredsquabbling on over credit for tion of ty-eigi anda dab    making ingenious and useful instruments—but not er admiration tions ofMiniature Bodies Made by Magnifying Glasses, produced in 1665. It revealed to an encedpublic a universe of t ructuredto imagining.

        Among tures first identified by tle cst ed t aone-in 1,259,712,000 of tiny cappearance of sucime ion or so, but     es of ty times, making t eentury optical teology.

        So it came as somet a decade later y began to receive dras from an uered linendraper in ions of up to 275 times. toni van Leeule formal education and no background insce, ive and dedicated observer and a teical genius.

        to t is not knoions from simpletle more t iny bubble ofglass embedded in t most of us t really not mucrument for everyexperiment remely secretive about ecimes offer tips to tis improve tions.

        2Over a period of fifty years—beginning, remarkably enougforty— to ty, all ten in Logue of ations, but simplyts of s on almosteveryt could be usefully examined—bread mold, a bee’s stinger, blood cells, teet, and semen (t ful apologies for ture)—nearly all of which had never been seen microscopically before.

        After ed finding “animalcules” in a sample of pepper er in 1676, ty spent a year    devices Englisectle animals” before finally getting tiLeeu tinybeings in a single drop of er—more teemed    no one ed.

        Inspired by Leeuidings, oto peer into microscopes    times found t    in fact tedDutcsoecker, le beings “ime many people believed t allures—ly inflated versions of tiny but pleteprecursor beings. Leeuhusiasms.

        In one of    successful experiments ried to study ties ofgunpo at cle; he process.

        2Leeuable, tist Jan Vermeer. I but not outstanding artist, suddenly developed tery of ligive for     ed t ing images onto a flat surface ted among Vermeers personal effects after    it    tor ofVermeers estate oni van Leeuive lens-maker of his day.

        In 1683 Leeu t    as far as progress could getfor t tury and a ations of microscope tetil1831    see t tisanistRobert Bro frequent but alo tory of sce. Bro nucleus from tin nucula, meaning little nut or kernel.

        Not until 1839,    all living matter is cellular. It , and it    only paratively late, as stifisig not    first. It    until teur in Fra it    arisespontaneously but must e from preexisting cells. t is the basis of all modern biology.

        to many t James trefil) to “a vast, teemiropolis” (t Guy Bro is like a refinery in t it is devoted to civityon a grand scale, and like a metropolis in t it is croeras t seem fused and random but clearly em to t it is amucmarisy or factory t you o begin y doesn’t meaningfully apply at t an atom’s ivity every    feel terribly electrical, but you are. t and to electricity. t give eac is t it is alliny scale: a mere 0.1 volts traveling distances measured in naers.

        up and it ranslate as a jolt of ty million volts per meter, abouttorm.

        ever t to fually the same plan:

        ter g or membrane, a nucleus ion to keep you going, and a busy space betoplasm. t, as most of us imagi, a durable, rubbery g, somet you is made up of a type of fatty material knoency “of a ligo quoteS seems surprisingly insubstantial, bear in mind t at tly. to anyter beesa kind of y gel, and a lipid is like iron.

        If you could visit a cell, you    like it. Bloo a scale at    tself oskeleton. it, millions upon millionsof objects—some tballs, ot likebullets. t be a place you could stand    being pummeled and rippedtimes every sed from every dire. Even for its full-time octs trand of DNA is on average attacked or damagedonce every 8.4 seds—ten times in a day—by cs t, and eac be sly stitc to perish.

        teins are especially lively, spinning, pulsating, and flying into eaco abillion times a sed. Eype of protein, daso a tasks a sed. Like greatly speeded up s, to t one. Some monitorpassing proteins and mark    are irreparably damaged or flaed, teins proceed to a structure called a proteasome, s used to build neeins. Some types of proteifor less t all lead existe areinceivably frenzied. As de Duve notes, “t necessarily remaiirely beyond tion oo t.”

        But sloo a speed at ions    be observed, and t seem quite so unnerving. You    see t a cell is just millions of objects—lysosomes,endosomes, ribosomes, ligands, peroxisomes, proteins of every size and somillions of ots and perf muasks: extrag energy from nutrients,assembling structures, getting rid of e, ruders, sending and receivingmessages, making repairs. typically a cell ain some 20,000 different types of protein,and of t 2,000 types    least 50,000 molecules. “t even if    only t in amounts of moretotal is still a very minimum of 100 million protein molecules in eacaggering figure gives some idea of ty of biocivity hin us.”

        It is all an immensely demanding process. Your    must pump 75 gallons of blood an’s enougo fill four Olympic-sized so keep all ted. (And t’s at rest. Duringexercise te    increase as mu up by tocations, and t a typical cell, t a cell does and    requires.

        You may recall from an earlier cer t toc to edas captive bacteria and t tially as lodgers in our cells, preserving tistrus, dividing to timetable, speaking t    tually all take into your body are delivered, after processing, to toced into a molecule called adenosiripe, or AtP.

        You may not P, but it is P molecules areessentially little battery packs t move t t of it. At any given moment, a typical cell in your bodyP molecules in it, and in tes every one of taken tP equivalent to about . Feel t’s your AtP at work.

        only be called great dignity. take doruts and buttresses t ogetly devour t parts. tosis rammed cell deat and billions of otly—for instance,    mostly told to.

        Indeed, if not told to live—if not given some kind of active instru from anotomatically kill t of reassurance.

        o expire in t rato divide and proliferate    cer. cer cells are really justfused cells. Cells make take fairly regularly, but temec. It is only very rarely t t of trol. Onaverage, al malignancy for eaillion billion cell divisions.

        cer is bad lu every possible sense of term.

        t t t t t a strettly sending andmonit streams of messages—a cacophe body:

        instrus, queries, corres, requests for assistance, updates, notices to divide or expire.

        Most of tities sucrogen, aostero vey information from remote outpostslike till otelegrapers in a process called parae signaling. Finally, cells unicatedirectly o make sure tions are coordinated.

        is per remarkable is t it is all just random frantic a, a sequence ofendless enters directed by notal rules of attra and repulsion.

        tions of t all just edly and so reliably t seldom are , yet some just order    a perfect    across the anism.

        In    and, trillions upon trillions of reflexive s add up to a mobile, to t, a rative but still incredibly anized dule. Every living t, is aomigineering.

        Indeed, some anisms t ive enjoy a level of cellular anizationt makes our orian. Disassemble tao a solution, and togeto a sponge again. You    do to to tio be.

        And t’s because of a curious, determined, barely uood molecule t is itself notalive and for t part doesn’t do anyt all. e call it DNA, and to begin touand its supreme importao sd to us o go back 160 years or so toVictorian England and to t    C    idea t aake a littleexplaining, locked it a fifteen years.
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