need help with your account or subscription? click here to email us (or see the contact page)
join telegramNEW! discord
jump to exam page:
search for anything ⋅ score predictor (“predict me!”)

You must be logged in to vote!
Retired NBME 21 Answers

nbme21/Block 3/Question#28 (reveal difficulty score)
A 1-year-old girl is admitted to the hospital ...
Disruption of the secondary structure of collagen molecules 🔍 / 📺 / 🌳 / 📖
tags: biochem

 Login (or register) to see more


 +16  upvote downvote
submitted by wasabilateral(47)
The site was recently locked🔒
It can be re-accessed by making a purchase.

Purchase your membership here
unscramble the site ⋅ become a member$279$49

I hnitk it ahs tnighosem ot od wtih iecyngl (due ot tsi mslla zies ti acn tif in aymn aeplsc rhewe roteh nmaoi dasic can not and neehc it rdioveps ucartr“lsut psse”ccmnato to the nlgoecal, .ie. upt a inkk in hte halpa x)e.ilh fI gleyicn is sidpamlce by inhtsmgeo s,lee I n’tdo khitn -rloglnaepoc nac fomr sti rcteorc roesdcyna uur.setrtc

unscramble the site ⋅ become a member$279$49
jotajota94  !uTer losa, nyeligc is /31 fo nclegalo alaf c,sianh os ti skame sesen tath situtotnsubi whti niaeanl hcw(ih is umhc b)irgge dwoul dale ot stopirnidu in hte palha xhile narftoo.mi +2
jotajota94  !euTr lsoa, cinygle si /31 of acllegon fala acih,sn os ti mksea eessn ahtt ibuuotstitsn wthi eainlna i(hhwc si cmhu igbrg)e duolw elad to pidrustion in teh hlapa hxile foaimton.r +
thepacksurvives  lGyenci si alslm and de,nby hhciw lwosal it to morf teh lbirfsi rfo eht iretpl hixel +
brasel  Aols ni alenreg AF( 8012 pg 05) IO is rofm rlmspbeo rmginfo the pirelt xilhe wchih is orasncedy ertuctusr. o,ayerlttunF tehy gave us tniesgohm to oranse wtih in hte suqteino &a(ylA-;lGtg) +3
amy  nCa oesomne ehlp me adrndenust why A is eron?tcicr 022A0F apge 5:0 prleTi exhli fo 3 lgolcnea a scihan is ermdfo form agrllconepo vai heydnogr adn eslfiuddi obdn. sI tish very rialsmi to athw A si n dciri?.eAgb desereaDc enndohbrgdyo- ifrmontoa etnweeb locleang lleuce.mos +
umpalumpa  ehT petnaanlixo gvine by swaltaaaiblre uoldc krow if the oiqtunes would say a-t&yglA-lG; oma.tntiu H,eveorw hte tqunseio atstes hatt eerth is na gGAa;l&--ytl .mntitoau +


You must be logged in to vote!

 +13  upvote downvote
submitted by cellgamesgojan(43)
The site was recently locked🔒
It can be re-accessed by making a purchase.

Purchase your membership here
unscramble the site ⋅ become a member$279$49

I dfeu,igr iy-XcYg-nel is elahtncclyi drdcienose a yrampri“ oimna aidc rrtcestuu of a ”toerpni seicn het edonifntii fo a yrriaPm stcuturer fo a ortepni is “a arieln cinha of moain .adcsi” If yuo mess whit eth iyrmaPr rusr,tcteu as in teh oesitnuq te,ms oyu acontn frmo eth dyaeSncro seurutctr fo eht optir,en whihc is mednrtieed by eth godrn-iybgoednnh chiwh rscocu netewbe the tpepeid ekoacnbb, netdeinpedn of eht R rpous.g I ohpe shti edma e.esns

oFrm epiiwdaik: d“oarycneS rtctusreu si orllmayf nidedfe by eth apntret of rnedygoh donsb enetebw teh maoni odyrngeh nad bxrlacyo neyxgo smota ni hte eptdeip obnkecab”. (shsaipem )inem

unscramble the site ⋅ become a member$279$49

From Molecular Biology of the Cell:

Biologists distinguish four levels of organization in the structure of a protein. The amino acid sequence is known as the primary structure of the protein. Stretches of polypeptide chain that form α helices and β sheets constitute the protein’s secondary structure. The full three-dimensional organization of a polypeptide chain is sometimes referred to as the protein’s tertiary structure, and if a particular protein molecule is formed as a complex of more than one polypeptide chain, the complete structure is designated as the quaternary structure.

https://www.ncbi.nlm.nih.gov/books/NBK26830/#A406

+5/- drdoom(1206)

You must be logged in to vote!

 +4  upvote downvote
submitted by usmle11a(102)
The site was recently locked🔒
It can be re-accessed by making a purchase.

Purchase your membership here
unscramble the site ⋅ become a member$279$49

ok gysu dna i otque ofrm osoe/datmpo-wtgl.n2/:weetceutlcpr/rsmihis4.poewa0tbi1she//oetrfscsit

09%" vahe na tinbaleedfii tingeec ntotaumi CL O 1A1 nda CLO 21A
usaesc mrlonaba eoglacnl gsocl-isniknr iav a eilgycn btsiosttiunu ni hte agllenoorpc ocellume "

hciwh sname ttah OI ahs a enigycl ttntuoisuibs nad rreetfho tsi ulneba to morf a rseyadocn uretusur.tc

unscramble the site ⋅ become a member$279$49


You must be logged in to vote!

 +4  upvote downvote
submitted by hungrybox(1277)
The site was recently locked🔒
It can be re-accessed by making a purchase.

Purchase your membership here
unscramble the site ⋅ become a member$279$49

euD ot cesg'niyl lasml ,izse it eetrsca "k"snki in het ianmo cadi usqne.ece heesT kikns rea dendee to cyerlortc ofmr eht ncasodyer uttesc.rur

rtOeh newr:ssa

  • d"eaewken toinacrinet etnbwee llegnoac dan epgryonoact"l - ngaolelc + tecroanlpyog = lcgaierla.t heT usnieotq tmes esiomntn amyn seefcdt in EObN eypt( I laegol)nc but on neomitn of etdcfes in alTrceWglaO p(tey II elcloa)gn
unscramble the site ⋅ become a member$279$49


You must be logged in to vote!

 +1  upvote downvote
submitted by basic_pathology(25)
The site was recently locked🔒
It can be re-accessed by making a purchase.

Purchase your membership here
unscramble the site ⋅ become a member$279$49

Y-ylG-X si cenbkabo fro econllga aalhp hac.ni 3 lcenoagl lhapa hnaics pislar to frmo rtlpie ieh.xl nyGceli ash no R uorpg, liawongl rfo llyeibxifit and imnoofatr of tleipr hle.xi oN inleygc etrnvsep hits nncousoiut nps,alrgii erngivnpte the tnafirmoo fo lcnaeolg dcoernysa .utsrcuetr

lleRac htat pea-chhlilsea nad seets-tbhae aer apeelmsx fo conesrday sr.eutstcur isTh nca be tugthoh of a ntofenasitiam of the alpah ilh.xe

unscramble the site ⋅ become a member$279$49


You must be logged in to vote!

 +0  upvote downvote
submitted by an_improved_me(91)
The site was recently locked🔒
It can be re-accessed by making a purchase.

Purchase your membership here
unscramble the site ⋅ become a member$279$49

rheNtAo ayw to etg at it si vai i:neltnimioa

.A ohergdny ndbngio ltodwun realyl cengha censi nertehi ninleaa nro iyclgen ear o.l rpBa lyG ;&tg Ala udsn'thlo ganhec woh ileprno is dfiemoid I( aenm ti OU,LDC if rtehe asw a eicsrt dahnircen ro mineo,shtg btu ton a ratge w .D)snera githonn to aeitncid ahtt aoeglcln dodteriegna si ledraet ni rseonsep to na AA ibtosstn.uuit lA,so in teh xentcto of OI hiwhc( is teh netnrgspie lcpon)ita,m ew ylardae wnok htat eth beoprml tn'sode vhea hatgnyni ot do ithw ng,raetioded oemr tiwh teh hcgean ni coruuit/.rEn utnetcsf ynleostH do'tn wokn.

unscramble the site ⋅ become a member$279$49


You must be logged in to vote!

 +0  upvote downvote
submitted by drdoom(1206)
The site was recently locked🔒
It can be re-accessed by making a purchase.

Purchase your membership here
unscramble the site ⋅ become a member$279$49

’eesHr oen ywa ot imoosrpcetif--eeasln dedar“esce ben-ondygrdho otnm”rfo:ia m’I otn a bgi nfa fo tish einl fo seiaong,rn but yctlnacilhe lnnieaa as a iesd rugop has emor srenoy*hgd rfo lpnetiota eryondgh dgoninb tahn lignyec:

ln:aeani —C3H
lnic:yeg —H

,oS h“inyaclc”,tel anliane owlud ptiemr roem odby-hgonrdne oa,mrfotni ihhcw mghti aolwl yuo to aeimtlein ttah .heicco

That asid, ti seems latosm eliisbmops ot uler tou htotw(iu evyr claitehnc edkolwegn or seom vpodired erexeanlitpm ad)ta ttah teh tllyhsig rgrela ninlaea sdeo ont iarimp rygendho ionbdgn weteneb loleagcn eeolumlsc iav stcire )aplaits( f.eetrieencnr In ierlpsm ,ermts secni lniaane is rlra,ge ouy douwl htkin tath it tusm emwohso eeeirrtnf wiht eht horoynnengddbgi- hatt crscou tihw eht piy-teldw ycelngi.

---
rci*tltyS gps,aiken i’ts not eth uenrbm of goerydhsn btu oasl teh hnesgrtt fo hte ledipo hatt italcetfisa dneogryh gdnbon:i a yronedhg duonb to a sroynglt necetlvagoirtee elmulceo keli nrieolfu wlil pepa”r“a eorm siviopte a,nd hs,ut e-gdnohdrbyon oemr slygnrot twhi a nbaery gnyxoe (ermocpda htiw a rgedynho cetndenoc ot ncr,boa for ma.lxepe)

ertruFh gria:nde

  1. hwldephhutc.m//pel.t/wtmoidrbwsudq/lesi../eugncphudh:
unscramble the site ⋅ become a member$279$49
hungrybox  Aiepctreap the ffoter but ihts is raf too glno ot eb uefus.l +30
drachenx  oxhyurnbg is a ikngeafr hraet +
drdoom  crx@hedan ,haah hn,a gnmcoi cbak ot sith i leizrae i saw bopbyral erngoiekeg-v llo +1
blueberrymuffinbabey  'isnt eht eyhdongr nibdnog peenddten on eth xylhadyerodt oliernp and seinly? so ahtt dt'onuwl yllaer be the siseu rehe sneic soeth teran' hte asa igenb lar?dete +
drdoom  reyubb@elr gcidAronc ot lArt’bse MoCB see( Tnnsateg ta rihg)t, xorydyynilehs dna rxyonlihroyped tcuboietnr oredgnhy dbons thta rmof wbeente hte isahnc r(h“a”ten,icni sa opodpes ot acitn;i-ahnr eth ncah,si fo ,socure are eeprsaat yedpesppli;to taht s,i tapseear algcolen ;soprteni and itsaceinnotr ebwtene eraeaspt ihsanc tae[erpsa tpdeipleysop] si ahwt we alcl atrunqrya“e ctureust”;r see ntTnaeg ebvoa.) dAn in this e,asc sa oyu tinpo ot,u eth smet ieessbcrd a tAyl-l&g;Ga titsusubi.tno aTth meses to eman owt ht:gnis (1) eht eethr tpaasere ogaenlcl eepyosppltid lliw tno p“kac ][as ”ilhgtty to mrof eth trelpi lhxei qyr(nateua=r s)rutecutr ew lla kwno dna ovel dna (2) oeniplr nsgir wlli fila ot erlay qtiue sa ,uysgln psoocgmnmiri eht elcailh oinofotrmnca hatt isfndee an hlpaa hacni dre(an=coys trrutcue;s het sspahe that rmfo ihnwit a snilge plpoiye)dp.te +
tadki38097  sola yuo t'acn H bond htiw car,bno st'i otn lpoar noeguh +
amy  0220FA 5P0 :esatt mofnoriat of clon(wcohlphraegi is hte irelpt xeihl tueusc)rtr vai gyrhonde dna d.dleisuif oS A si rircctoen bc rthee are on celaglon luolscmee yet nd(2 ueutcrrst peanhps at glnlaropcoe le)lev +
drdoom  yam@ lpietr xihel is a rruaeatqyn rutserutc (ecisn rlpite hlexi si a epahs ahtt ofsmr EBTENEW retspaea or au”t“dl eoponc-e/laaclgngllor psetip).de maP,iryr nredosyca adn tiytrear tusrcusret rea pdirsesnicot fo a esgnli leptdoip.yep nceO yuo haev 2 or orem odpeesptilpy enrtgactnii twih ehca hreot ,(.e.g gooliHmben oemluec)l uyo eahv urnerqayat trsute.ruc +

From Molecular Biology of the Cell:

Hydroxylysines and hydroxyprolines are infrequently found in other animal proteins, although hydroxyproline is abundant in some proteins in the plant cell wall. In collagen, the hydroxyl groups of these amino acids are thought to form interchain hydrogen bonds that help stabilize the triple-stranded helix. Conditions that prevent proline hydroxylation, such as a deficiency of ascorbic acid (vitamin C), have serious consequences. (Emphasis mine)

https://www.ncbi.nlm.nih.gov/books/NBK26810/#A3555

+1/- drdoom(1206)

From Molecular Biology of the Cell:

The primary feature of a typical collagen molecule is its long, stiff, triple-stranded helical structure, in which three collagen polypeptide chains, called α chains, are wound around one another in a ropelike superhelix (Figure 19-43). Collagens are extremely rich in proline and glycine, both of which are important in the formation of the triple-stranded helix. Proline, because of its ring structure, stabilizes the helical conformation in each α chain, while glycine is regularly spaced at every third residue throughout the central region of the α chain. Being the smallest amino acid (having only a hydrogen atom as a side chain), glycine allows the three helical α chains to pack tightly together to form the final collagen superhelix (see Figure 19-43).

https://www.ncbi.nlm.nih.gov/books/NBK26810/#_A3551_

+/- drdoom(1206)

You must be logged in to vote!

 +0  upvote downvote
submitted by nmb29(0)
The site was recently locked🔒
It can be re-accessed by making a purchase.

Purchase your membership here
unscramble the site ⋅ become a member$279$49

I mithg eb knhtirviogne ti bu,t H obnd oftnaromi of aa's eakms teh snyrcdoea tutsrurce fo hte nproite olg(lcaen ni isht ce.sa) eTh ylG to aAl titnitssbouu sedo estlur in lses H obdn fnaroomi,t tub fo vidinliuda aa's not bteewen gaconell ecsllmoeu (ahtt imght be moer for atyuaneqrr ucut)trres

unscramble the site ⋅ become a member$279$49
lpp06  I ntkhi eth eky is in hte nsawre risap,hng the awenrs tminigenon bHnsod- yssa uDniipto"rs of -dsHnob bnteewe eaclnogl leelgohmusuAct"o lh goalcnel esdo druegno oHi-ngbdn ot ptrupso teh ipetrl e,lixh sthi si dnoe iwnith eth mesa llcogane koLiigmu.nc lelne ffrtenied eganclol lselcmuoe urcsoc avi teh ynseli - exsyolniryhdy inlks oend ni teh CME +1
kevin  thsi is hte eon ocmnmet htta flyalin eplhde em andsnrudet hwy htat swa .nctcireor khtan uyo +


You must be logged in to vote!

 +0  upvote downvote
submitted by j123(16)
The site was recently locked🔒
It can be re-accessed by making a purchase.

Purchase your membership here
unscramble the site ⋅ become a member$279$49

miyPrar uusrectrt = oainm caid n eynaquceroSescde sueuttcrr = tsrruteuc oefmdr thiw a ilnges aomin cdia equneesc btea( edtpael hete,s lapah exi,lh tcryar)ete iT ttucuresr = mtepliul dornscaey uurtctsser cinrtigtena thoreteg lemiltpu( taeb detelpa setesh ctsdkea on top fo chea ,tehor ectryrt aaQruen) sctutreru = neporti eucrtstur ormdfe rfmo fndiglo fo lla erttirya srruetsutc to ekam ingnibd s,iset t.ce

cieSn the aiaelnn swa put in clpae of het eyGil,nc eth pirarym cretruust swa lnubea to rmof an apahl hliex secni aaplh hliex resrtusctu ndee a utrraipacl eecnsqeu lgy( - x- )y in oerrd ot from ydegrhno dobns ot ekpe hte xelhi besla.t

unscramble the site ⋅ become a member$279$49


You must be logged in to vote!

 -1  upvote downvote
submitted by unknown001(9)
The site was recently locked🔒
It can be re-accessed by making a purchase.

Purchase your membership here
unscramble the site ⋅ become a member$279$49

htaw is llgoenac ? a erysdanco iteponr utturc.esr

hnwe yuo eemrvo ,geciynl the mtos ananbtud aniom idac , mrof teh reurprcso eeocmllu ilwl oyu egt a ppoerr ndyeacsor seruutrtc ? ON

unscramble the site ⋅ become a member$279$49
unknown001  ioergn htis +
drdoom  cna you t?aoralbee t'whas grnwo tihw oruy mem?ntco +


You must be logged in to vote!

 -4  upvote downvote
submitted by lilmonkey(63)
The site was recently locked🔒
It can be re-accessed by making a purchase.

Purchase your membership here
unscramble the site ⋅ become a member$279$49

lGy is ,aoplr annlieA si aonnoplr adn co.yhrhpobdi sienMses teoarnvicvesonn u.oitnmta Tehse AAs veah rnetediff cmiacelh epstierrpo cihwh eadl to dpseidutr eopnitr oindlgf (nacedyros sc.u)ettrru iaSrmli ot lGu - alV utsboitnuist ni eSlcki lCel Diae.sse

unscramble the site ⋅ become a member$279$49


You must be logged in to vote!

Must-See Comments from nbme21

nosancuck on Absorption atelectasis
assoplasty on Free T4
seagull on GM2
lnsetick on Apocrine
niboonsh on NMDA receptors are blocked by Mg2+ at the ...
drdoom on Deletion of a hydrophobic amino acid ...
hayayah on HCO3− transported in the plasma
mcl on Aortic
notadoctor on Usual interstitial pneumonitis
madojo on Genital herpes
hungrybox on Obstruction of the bile duct
jambo2222 on Lung
hungrybox on Mismatch repair
hungrybox on Hydrochlorothiazide

search for anything NEW!