koshika

koshika

koshika (Cell) sajeevon ke shareer ki rachanaatmak aur kriyaatmak ikaai hai aur praaya: svat: janan ki saamarthya rakhati hai. yeh vibhinn padaarthon ka vah chhote-se-chhota sangathit rup hai jismein ve sabhi kriyaaeain hoti hain jinhein saamoohik roop se ham jeevan kahatein hain.

'koshika' ka angreji shabd sel (Cell) laitin bhaasha ke 'shelula' shabd se liya gaya hai jiska arth 'ek chhota kamara' hai. kuchh sajeev jaise jeevaanuon ke shareer ek hi koshika se bane hote hain, unhein ekakoshakeeya jeev kehte hain jabki kuchh sajeev jaise manushya ka shareer anek koshikaaon se milkar bana hota hai unhein bahukoshakeeya sajeev kehte hain. koshika ki khoj Robert hook ne 1665 i0 mein kiya.[1] 1939 i0 mein shlaaiden tatha shvaan ne koshika siddhaant prastut kiya jiske anusaar sabhi sajeevon ka shareer ek ya ekaadhik koshikaaon se milkar bana hota hai tatha sabhi koshikaaon ki utpatti pehle se upasthit kisi koshika se hi hoti hai.

sajeevon ki sabhi jaivik kriyaaeain koshikaaon ke bheetar hoti hain. koshikaaon ke bheetar hi aavashyak aanuvaanshik soochanaaeain hoti hain jinse koshika ke kaaryon ka niyantran hota hai tatha soochanaaeain agali peedhi ki koshikaaon mein sthaanaantarit hoti hain.[2]

koshikaaon ka vidhivt adhyayan koshika vigyaan (Cytology) ya 'koshika jaiviki' (Cell Biology) kahalaata hai.

anukram

aavishkaar evam anusandhaan ka itihaas

  • Robert huk ne 1665 mein botal ki kaark ki ek patali parat ke adhyayan ke aadhaar par madhumakkhi ke chhatte jaise koshth dekhe aur inhein kosha naam diya. yeh tathya unki pustak maaikrograafiya mein chhapa. raabart huk ne kosha-bhittiyon ke aadhaar par kosha shabd prayog kiya.
  • 1674 entoni vaun lyoovenhauk ne jeevit kosha ka sarvapratham adhyayan kiya.
  • 1831 mein Robert brown ne koshika mein 'kakeindrak evam keindrika' ka pata lagaaya.
  • tadarochit naamak vaigyaanik ne 1824 mein koshaavaad (cell theory) ka vichaar prastut kiya, parantu iska shreya vanaspati-vigyaan-shaastri shlaaiden (Matthias Jakob Schleiden) aur jantu-vigyaan-shaastri shvaan (Theodor Schwann) ko diya jaata hai jinhonne theek prakaar se koshaavaad ko (1839 mein) prastut kiya aur batalaaya ki 'koshaaeain paudhon tatha jantuon ki rachanaatmak ikaai hain.'
  • 1953: Watson aur krik (Watson and Crick) ne DNA ke 'double-heliks sanrachana' ki pehli baar ghoshana ki.
  • 1981: lin maargulis (Lynn Margulis) ne koshika kram vikaas mein 'sibiyos' (Symbiosis in Cell Evolution) par shodhapatr prastut kiya.

prakaar

do prakaar ki koshikaaeain : yookairotik (baaeain) tatha prokairiotik (daaeain)

koshikaaeain do prakaar ki hoti hain,

prokairiyotik koshikaaeain praay: svatantr hoti hain jabki yookairiyotik koshikaaeain, bahukosheeya praaniyon mein paayi jaati hain. prokairiyotik koshika mein koi spasht kendrak naheen hota hai. kendrakeeya padaarth koshika drav mein bikhre hote hain. is prakaar ki koshika jeevaanu tatha neeli hari shaivaal mein paayi jaati hai. sabhi uchch shreni ke paudhon aur jantuon mein yookairiyotik prakaar ki koshika pai jaati hai. sabhi yookairiyotik koshikaao mein sangathit kendrak paaya jaata hai jo ek aavaran se dhaka hota hai.

koshika sanrachana

koshikaaeain sajeev hoti hain tatha ve sabhi kaarya karti hain, jinhein sajeev praani karte hain. inka aakaar atisookshm tatha aakruti golaakaar, andaakaar, stanbhaakaar, romakayukt, kashaabhikaayukt, bahubhujeeya aadi prakaar ki hoti hai. ye jeli jaisi ek vastu dvaara ghiri hoti hain. is aavaran ko koshikaavaran (cell membrane) ya koshika-jhilli kehte hain yeh jhilli avakaleeya paaragamya (selectively permeable) hoti hai jiska arth hai ki yeh jhilli kisi padaarth (anu ya oyan) ko mukt roop se paar hone deti hai, seemit maatra mein paar hone deti hai ya bilkul rok deti hai. ise kabhi-kabhi 'jeevadravya kala' (plasma membrane) bhi kaha jaata hai. iske bheetar nimnalikhit sanrachanaaeain pai jaati hain:-

(1) keindrak evam keindrika
(2) jeevadravya
(3) golgi sammishr ya golgi yantr
(4) kanaabh sootr
(5) antarpradravya daalika
(6) gunasootr (pitrusootr) evam jeen
(7) raaibosom tatha sentrosom
(8) lavak

kuchh khaas bhinnataaon ko chhod sabhi prakaar ki koshikaaon, paadap evam jantu koshika ki sanrachana lagbhag ek jaisi hoti hai. ye sajeev aur nirjeev donon tarah ki ikaaiyon se milkar bani hoti hain. ek saamaanya koshika ya praaroopik koshika ke mukhya teen bhaag hain, koshikaavaran, koshika dravya evam kendrak. koshikaavaran koshika ka sabse baahar ka aavaran ya ghera hai. paadap koshika mein koshika bhitti aur koshika jhilli milkar koshikaavaran ka nirmaan karte hain. jantu koshika mein koshika bhitti naheen pai jaati at: koshika jhilli hi sabse baahari aavaran hai. koshika jhilli evam kendrak ke beech ke bhaag ko koshika dravya kaha jaata hai, ismein vibhinn koshikaang hote hain. kendrak koshika ke andar paaye jaane waali ek gol evam saghan rachana hai. kendrak ko koshika ka 'mastishk' kaha jaata hai. jis prakaar shareer ke saare kriyaayon ka niyantran mastishk karta hai theek usi prakaar koshika ke saare kaaryon ka niyantran kendrak dvaara hota hai.

keindrak

ek koshika mein saamaanyat: ek hi keindrak (nucleus) hota hai, kintu kabhi-kabhi ek se adhik keindrak bhi paae jaate hain. koshika ke samast kaaryon ka yeh sanchaalan kendra hota hai. jab koshika vibhaajit hoti hai to iska bhi vibhaajan ho jaata hai. keindrak koshika ke bheetar ek taral padaarth koshikaadravya (cytoplasm) mein praaya: tairata rahata hai. iska yadyapi koi nishchit sthaan naheen hota, tathaapi yeh adhiktar lagbhag madhyabhaag mein hi sthit hota hai. kuchh koshikaaon mein iski sthiti aadhaareeya (basal) aur kuchh mein seemaanteeya (peripheral) bhi hoti hai. keindrak ki aakruti golaakaar, vartulaakaar ya andaakaar hoti hai. tathaapi, kabhi-kabhi yeh belanaakaar, deerghavruttaakaar, sapaat, shaakhaanvit, naashapaati jaisa, bhaalaakaar aadi svaroopon ka bhi ho sakta hai. iske bheetar keindrakaras (nuclear sap) keindrika (nucleolus) tatha pitrusootr (chromosomes) paae jaate hain. keindrak ke aavaran ko keindrakakala (nuclear membrance or nucleolemma) kehte hain.

keindrika (Nucleolus)

pratyek keindrak mein ek ya adhik keindrikaaeain pai jaati hain. koshika vibhaajan ki kuchh vishesh avastha mein keindrika lupt ho jaati, kintu baad mein pun: prakat ho jaati hai. keindrika ke bheetar ribonyookleeik aml (ritioncleric acid or RNA) tatha kuchh vishesh prakaar ke enjaaim adhik maatra mein paae jaate hain. keindrika sootran (mitosis) ya sootri vibhaajan mein mahatvapoorn bhoomika ada karte hain.

jeevadravya (protoplasm)

yeh ek gaadha taral padaarth hota hai jo sthaanavishesh par vishesh naamon dvaara jaana jaata hai; jaise, dravyakala (plasma membrane) tatha keindrak ke madhyavarti sthaan mein paae jaane vaale jeevadravya ko koshikaadravya (cyt plasm) aur keindrak jhilli (nuclear membrane) ke bheetar paae jaane vaale jeevadravya ko keindrak dravya (nucleoplasm) kehte hain. koshika ka yeh bhaag atyant chaitanya aur koshika ki samast jaiveeya prakriyaaon ka kendra hota hai. ise iseeliye 'sajeev' (living) kaha jaata hai. jeev vaigyaanik ise 'jeevan ka bhautik aadhaar' (physcial basis of life) naam se sambodhit karte hain. aadhunik jeev vaigyaaniko ne jeevadravya ka raasaayanik vishleshan karke yeh to pata laga liya hai ki usaka nirmaan kin-kin ghatakon dvaara hua hai, kintu aaj tak kisi bhi vaigyaanik ko usamein (jeevadravya) praan ka sanchaar karne mein safalta haath naheen lagi hai. aisa hai yeh prakruti ka rahasyamaya padaarth.

jeevadravya ka nirmaan kaarban, haaidrojan, okseejan tatha anek kaarbanik (organic) tatha akaarbanik (inorganic) padaartho dvaara hua hota hai. ismein jal ki maatra lagbhag 80% proteen 15%, vasaaeain 3% tatha carbohydrate 1% aur akaarbanik lavan ki 1 hoti hai. jeevadravyon ke kai prakaar hote hain, jaise kolaaid (colloid), kanaabh (granular), tantumaya (fibrillar), jaaleedaar (reticular), koopikaakaar (alveolar), aadi.

golgi sammishr ya yantr (Golgi complex or apparatus)

is ang ka yeh naam iske khojakarta kaimilo golgi, ke naam par pada hai, jinhonne 1898 mein sarvapratham iski khoj ki. yeh ang saadhaaranat: keindrak ke sameep, akele ya samoohon mein paaya jaata hai. iski rachana teen tatvon (elements) ya ghatakon (components) dvaara hui hoti hai : sapaat kosh (flattened sacs), badi badi riktikaaeain (large vacueles) tatha aashay (vesicles). yeh ek prakaar ke jaal (network) jaisa dikhlaai deta hai. inka mukhya kaarya koshikeeya sravan (cellular secretion) aur proteenon, vasaaon tatha katipya kinvon (enzymes) ka bhadaaran karna (storage) hai.

kanaabhasootr (Mitochondria)

ye kanikaaon (granules) ya shalaakaaon (rods) ki aakrutivaale hote hain. ye angak (organelle) koshikaadravya (cytoplasm) mein sthit hote hain. inki sankhya vibhinn jantuon mein paaainch lakh tak ho sakti hai. inka aakaar 1/2 maaikraun se lekar 2 maaikraun ke beech hota hai. virl udaaharanon (rare cases) mein inki lanbaai 40 maaikraun tak ho sakti hai. inke anek kaarya batalaae gaye hain, jo inki aakruti par nirbhar karte hain. tathaapi inka mukhya kaarya koshikeeya shvasan (cellular respiration) batalaaya jaata hai. inhein koshika ka 'power plant' (power plant) kaha jaata hai, kyonki inse aavashyak oorja (energy) ki aapoorti hoti rahati hai.

antarpradravya jaalika (fndoplasmic reticulum)

yeh jaalika koshikaadravya (cytoplasm) mein aashayon (vesicles) aur nalikaaon (tubules) ke roop mein faili rahati hai. iski sthiti saamaanyat: keindrakeeya jhilli (nuclear membrane) tatha dravyakala (plasma membrane) ke beech hoti hai, kintu yeh aksar sampoorn koshika mein faili rahati hai. yeh jaalika do prakaar ki hoti hai : chikni satahavaali (smooth surfaced) aur khuraduri satahavaali (rough surfaced). iski satah khuraduri isliye hoti hai ki is par raaibosom (ribosomes) ke kan bikhre rahate hain. iske anake kaarya batalaae gaye hain, jaise yaantrik aadhaaran (mechanical support), dravyon ka pratyaavartan (exchange of materials), ant: koshikeeya abhigman (intracellular transport), proton sanshleshan (protein synthesis) ityaadi.

gunasootr ya pitrusootr (chromosomes)

yeh shabd krom (chrom) tatha soma (soma) shabdon se milkar bana hai, jiska arth hota hai : rangeen pind (colour bodies). gunasootr keindrakon ke bheetar jodon (pairs) mein paae jaate hain aur koshika vibhaajan ke saath keindrak sahit baaaint jaaya karte hain. inmein sthit jeevon ki poorvajon ke paitrik gunon ka vaahak kaha jaata hai. inki sankhya jeevon mein nishchit hoti hai, jo ek do jodon se lekar kai sau jodon tak ho sakti hai. inka aakaar 1 maaikraun se 30 maaikraun tak (lamba) hota hai. inki aakruti saadhaaranat: angreji bhaasha ke akshar S jaisi hoti hain. inmein nyooklio-proteen (nucleoprotein) mukhya roop se paae jaate hain. pitrusootron ke kuchh vishesh prakaar bhi paae jaate hain, jinhein lainpabrash pitrusootr (lampbrush chromosomes) aur poloteen kromosom (polytene chromosomes) ki sanjnyaa di gayi hai. inhein W, X, Y, Z, aadi naamon se sambodhit kiya jaata hai.

jeen (gene)

jeenon ko paitrik gunon ka vaahak (carriers of hereditary characters) maana jaata hai. kromosom ya pitrusootron ka nirmaan histon proteen tatha diokseeraaibonyooklik aisid (DNA) tatha raaibonyooklik aisid (RNA) se milkar hua hota hai. jeen ka nirmaan inheen mein se ek, dee॰ ena॰ e॰ dvaara hota hai. koshika vibhaajanon ke falasvaroop jab nae jeev ke jeevan ka sootrapaat hota hai, to yahi jeen Patrick evam shareerik gunon ke saath maata pita se nikalkar santatiyon mein chale jaate hain. yeh aadaan pradaan maata ke dinb (ovum) tatha pita ke shukraanu (sperms) mein sthit jeenon ke dvaara sampann hota hai. san‌ 1970 ke June maas mein amareeka sthit bhaarateeya vaigyaanik shri haragovind khuraana ko krutrim jeen utpann karne mein abhootapoorv safalta mili thi. inhein san‌ 1978 mein Nobel puraskaar mila tha.

ribosom (ribosomes) seintrosom (centrosomes)

sookshm gulikaaon ke roop mein praapt in sanrachanaaon ko keval ilektraun maaikrauskop ke dvaara hi dekha ja sakta hai. inki rachana 50% proteen tatha 50% aara॰ ena॰ e॰ dvaara hui hoti hai. ye visheshakar antarpradravya jaalika ke oopar paae jaate hain. inmein proteenon ka sanshleshan hota hai.

seintrosom (centrosomes)– ye keindrak ke sameep paae jaate hain. inke ek vishesh bhaag ko seintrosfeeyar (centrosphere) kehte hain, jiske bheetar seintriolon (centrioles) ka ek joda paaya jaata hai. koshika vibhaajan ke samay ye vibhaajak koshika ke dhruv (pole) ka nirdhaaran aur kuchh koshikaaon mein kashaabhika (flagella) jaisi sanrachanaaon ko utpann karte hain.

lavak (plastids)

lavak adhiktar paudhon mein hi paae jaate hain. ye ek prakaar ke ranjak kan (pigment granules) hain, jo jeevadravya (protoplasm) mein yatr tatr bikhre rahate hain. klorofil (chlorophyll) dhaarak varn ke lavak ko harit‌ lavak (chloroplas) kaha jaata hai. isi ke kaaran vrukshon mein haraapan dikhlaai deta hai. klorofil ke hi kaaran ped paudhe prakaash sanshleshan (photosynthesis) karte hain. kuchh vaigyaaniko ke mataanusaar lavak koshikaadravyeeya vanshaanugati (cytoplasmic inheritance) ke roop mein koshika vibhaajan ke samay santati koshikaaon mein seedhe seedhe sthaanaantarit ho jaate hain.

kaarya

vruddhi tatha chayaapachaya

srujan

proteen sanshleshan

sandarbh

  1. "... I could exceedingly plainly perceive it to be all perforated and porous, much like a Honey-comb, but that the pores of it were not regular [..] these pores, or cells, [..] were indeed the first microscopical pores I ever saw, and perhaps, that were ever seen, for I had not met with any Writer or Person, that had made any mention of them before this. . ." – Hooke describing his observations on a thin slice of cork. Robert Hooke
  2. Maton, Anthea; Hopkins, Jean Johnson, Susan LaHart, David Quon Warner, Maryanna Wright, Jill D (1997). Cells Building Blocks of Life. New Jersey: Prentice Hall. aai॰aऍsa॰abee॰aऍna॰ 0-13-423476-6.

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