Transcript G Biyoloji Ders 1
Konu 1
Canlılığın incelemesi
PowerPoint Lectures for
Biology, Seventh Edition Neil Campbell and Jane Reece
Lectures by Chris Romero
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Biyoloji Nedir?
• Canlıları inceleyen bilim dalıdır • Mikroskobik seviye • Makroskobik seviye • Küresel seviye • Yapı,fonksiyon,büyüme,evrim,dağılım, taksonomi, filogeni, çeşitlilik Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Biyolojik Organizasyon Düzeyleri
• Biyosforden - Organizmaya
1 Biyosfer 1 Ekosistem Komünite Populasyon Organizma a Fig ür 1.4
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• Organdan Hücre - Moleküle Cell
9 Organeller
1 µm
8 Hücre
Atoms
10 Mole küller
50 µm
7 Doku 6 Organ Fig ür 1.4
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 10 µm
Hücreye yakın bir bakış
• Hücre yaşam için gerekli olan tüm aktivitelerin gerçekleştiği, biyolojik organizasyonun en küçük seviyesi
Fig ür 1.9
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 25 µm
Hücre’nin iki önemli formu
• Tüm hücreler • – – Membran tarafından çevrilmiş EUKARYOTIC CELL Genetik bilgi olarak DNA Membrane Cytoplasm İki form hücre – Ökaryotik – Prokaryotik Organelles Nucleus (contains DNA) Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings PROKARYOTIC CELL DNA (no nucleus) Membrane 1 µm
Yaşamın üç Domain’i
• Yaşam en üst seviyede 3 domain’den oluşur – Bakteri – Archaea – Eukarya Prokaryotik canlılar Protista Bitki Mantar Hayvan Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
3 domain Bacteria
are the most diverse and widespread prokaryotes 4 µm and are now divided among multiple kingdoms. Each of the rod-shaped structures in this photo is a bacterial cell.
DOMAIN ARCHAEA
Protists
(multiple kingdoms) 100 µm are unicellular eukaryotes and their relatively simple multicellular relatives.Pictured here is an assortment of protists inhabiting pond water. Scientists are currently debating how to split the protists into several kingdoms that better represent evolution and diversity.
Kingdom Plantae
consists of multicellula eukaryotes that carry out photosynthesis, the conversion of light energy to food.
Fig ür 1.15
Many of the prokaryotes known as
archaea
live in Earth‘s 0.5 µm extreme environments, such as salty lakes and boiling hot springs. Domain Archaea includes multiple kingdoms. The photo shows a colony composed of many cells.
Kindom Fungi
is defined in part by the nutritional mode of its members, such as this mushroom, which absorb nutrientsafter decomposing organic material.
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Kindom Animalia
consists of multicellular eukaryotes that ingest other organisms.
Konu 2
Canlıların kimyasal içeriği
• Element • Bileşik PowerPoint Lectures for
Biology, Seventh Edition Neil Campbell and Jane Reece
Lectures by Chris Romero
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Element
• Kimyasal tepkimelerle başka bileşiklere parçalanamayan maddelerdir • 92 element • Atom lar’dan oluşmuştur • carbon C , hydrogen H , oxygen O ve nitrogen N bir organizmanın 96% oluşturan zorunlu elementlerdir Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Diğer elementler
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
İz element
• Çok az miktarda olsa da organizmaın ihtiyaç duyduğu element • Fe ve Zn Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Bileşik
• Belirli bir oranda bir araya gelen iki veya daha fazla element içeren madde • NaCl (1:1), H 2 O (2:1) • Elemetlerinden farklı karakterlere sahip + Figür 2.3
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Atom
• Maddenin en küçük parçası • Her elementin belirli atom çeşidi var Nötron Proton Elektron ?
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Kimyasal Bağ
• Kovalent • İyonik kuvvetli • Zayıf Kimyasal Bağlar • Hidrojen bağı Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Kovalent Bağ
Name (molecular formula) (c) Water (H 2 O).
Two hydrogen atoms and one oxygen atom are joined by covalent bonds to produce a molecule of water.
(d) Methane (CH 4 ).
Four hydrogen atoms can satisfy the valence of one carbon atom, forming methane.
Electron shell diagram
Figür 2.12
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings O H
Structural formula
H H H C H H
Space filling model
Iyonik Bağ
• Atomlar arasında elektron transferi 1 The lone valence electron of a sodium atom is transferred to join the 7 valence electrons of a chlorine atom.
Na Cl
Na
Sodium atom (an uncharged atom)
Cl
Chlorine atom (an uncharged atom) Fig ür 2.15
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 2 Each resulting ion has a completed valence shell. An ionic bond can form between the oppositely charged ions.
+ –
Na Cl
Na +
Sodium on (a cation)
Cl
Sodium chloride (NaCl)
–
Chloride ion (an anion)
Hidrojen Bağı (Zayıf)
Water (H
2
O) Ammonia (NH
3
) H + O H + – N H H H + A hydrogen bond results from the attraction between the partial positive charge on the hydrogen atom of water and the partial negative charge on the nitrogen atom of ammonia.
Fig ür 2.16
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Konu 3
Biyolojik Moleküllerin yapısı
PowerPoint Lectures for
Biology, Seventh Edition Neil Campbell and Jane Reece
Lectures by Chris Romero
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Makromole küller
– Küçük moleküllerden oluşan büyük moleküller – Yapısal olarak kompleks – Kovalent bağ
Fig ür 5.1
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Makromole küller
• Çoğu Makromolekül monomer lerden oluşmuş polimer lerdir • Dört önemli organik molekül (ilk 3 polimerdir) – Karbohidrat – Protein – Nucleik asid – Lipid Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 21
• Polimer – Monomer olarak bilinen ve tekrarlanan birimlerin bir araya gelmesi – Her monomer kendine özgü polimeri oluşturur – Örn: amino acidler proteinlerin monomeri 22 Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Polimerlerin oluşumu ve parçalanması
• Monomerler dehidrasyon tepkimesi ile daha büyük molekülleri oluşturur • H 2 O çıkışı • Hidroksil (-OH) ve Hidrojen (-H) grubu
Figür 5.2a
HO
1 2
Short polymer
3 H
Dehydration removes a water molecule, forming a new bond
HO H 2 O
H Unlinked monomer HO
1 2 3 4
H Longer polymer
Dehydration reaction in the synthesis of a polymer
23 Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Polimerlerin oluşumu ve parçalanması
• Polimerler monomerlerine ortama H 2 O ilavesi ile ( Hidroliz ) parçalanabilir • -H bir monomere, OH diğer monomere HO
1 2 3 4
H Hydrolysis adds a water molecule, breaking a bond
H 2 O Figür 5.2b
HO
1 2 3 Hydrolysis of a polymer H HO
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings H 24
Karbohidratlar
•
Şeker ve bunların polimerlerini (nişasta, selüloz) içerir
•
Monosakkarit ler en basit şeker
•
İki mososakkarit+kovalent bağ= Disakkarit
25 Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• Örnek monosakkaritler
Triose sugars (C 3 H 6 O 3 )
H O C H C OH H C OH H Glyceraldehyde
Pentose sugars (C 5 H 10 O 5 )
H O C H C OH H C OH H C OH H C OH H Ribose
Figür5.3
H H C OH C O H C OH H Dihydroxyacetone H H C OH C O H C OH H C OH H C OH H Ribulose
Hexose sugars (C 6 H 12 O 6 )
H O C H C OH HO C H H C OH H C OH H C OH H Glucose H O C H C OH HO C H HO C H H C OH H C OH H Galactose H H C OH C O HO C H H C OH H C OH H C OH H Fructose 26 Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• Monosakkaritler – Doğrusal (linear) – Halkasal (ring) H 1 C O 4 H C OH OH 6 CH 2 OH 5 C H 4 C H OH OH 3 C H O H 2 C 1 C H H O OH 6 CH 2 OH H 5 C 4 C OH 3 C H OH H O 2 H 1 C C OH H OH H HO 4 CH 2 OH 6 O 5 H OH 3 2 H 1 OH H OH
Figür 5.4
H (a) Linear and ring forms. Chemical equilibrium between the linear and ring structures greatly favors the formation of rings. To form the glucose ring, carbon 1 bonds to the oxygen attached to carbon 5.
27 Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
•
Disakkaritler
–
İki monosakkarit
–
Glikozidik bağ
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Maltoz &Sükroz
(a) Dehydration reaction in the synthesis of
maltose. The bonding of two glucose units forms maltose. The glycosidic link joins the number 1 carbon of one glucose to the number 4 carbon of the second glucose. Joining the glucose monomers in a different way would result in a different disaccharide. H HO CH H H 2 OH O H OH H OH
Glucose
OH H 2 O H O H CH OH H H H 2 OH O H OH
Glucose
H
(b)
H O a disaccharide formed from glucose and fructose.
Notice that fructose, though a hexose like glucose, forms a five-sided ring.
CH 2 O H H O H O H H H O H
Glucose
O H H 2 O H O CH 2 OH O H OH H HO CH 2 OH H
Fructose Figür 5.5
H HO CH 2 OH H O O H H H 1 1–4 glycosidic linkage O H OH 4 H CH 2 OH H H O O H H OH H OH
Maltose
H HO CH 2 OH H O H O H H OH H 1 1–2 glycosidic linkage O 2 CH 2 OH O H HO H CH 2 OH OH H
Sucrose
29 Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• Polisakkaritler – Şeker polimeri – Organizmada çeşitli rol • Depo polisakkaritleri • Yapısal polisakkaritler Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 30
Depo polisakkaritleri
• Nişasta Chloroplast Starch – Glikoz monomerlerinden oluşan polimer – Bitkilerde glikozun depo edilmesini sağlar 1 m – Plastid
Amylose Amylopectin
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 5.6
(a) Starch: a plant polysaccharide
31
• Glikojen – Glikoz monomerlerini içerir – Hayvanlarda ana depo maddesi, dallanma Mitochondria Giycogen granules 0.5 m
Glycogen Figure 5.6
(b) Glycogen: an animal polysaccharide
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 32
Yapısal Polisakkaritler
• Selüloz – Glikoz polimeri – Bitki hücreleri – Nişastadan farkı?? (-OH) – Doğrusal, dallanmaz Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 33
Selüloz&Nişasta 4 H HO CH 2 OH H O OH H H H OH glucose
OH
H HO H H H H C C C C C C O OH H OH OH OH H 4 HO CH 2 OH O H OH H H
OH
H 1 OH glucose
Figure 5.7 A–C
HO
(a)
and
glucose ring structures
CH OH 2 OH O 1 O 4 CH 2 OH O OH 1 O 4 HO CH OH 2 OH O 1 O 4 OH OH OH
(b) Starch: 1– 4 linkage of
glucose monomers
CH 2 OH O OH OH 1 O 4 OH O OH CH 2 OH
(c) Cellulose: 1– 4 linkage of
O CH OH 2 OH O OH
glucose monomers
O Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings CH 2 OH O OH 1 O OH OH OH O CH 2 OH OH 34
Bitki hücre duvarında dayanıklılığı sağlayan yapı Cell walls Cellulose microfibrils in a plant cell wall Microfibril About 80 cellulose molecules associate to form a microfibril, the main architectural unit of the plant cell wall.
0.5 m Plant cells Parallel cellulose molecules are
Figure 5.8
held together by hydrogen bonds between hydroxyl groups attached to carbon atoms 3 and 6.
CH 2 OH OH O O O H CH 2 OH OH O O O H CH 2 OH O OH O O H OH O OHO CH 2 OH O O O CH OH 2 OH OH OH OH O CH 2 OH O CH 2 OH OH O O CH 2 OH OH O OH CH 2 OH OH O O O O CH OH 2 OH OH OH CH 2 OH OH OH OH CH 2 O OH O O O Glucose monomer Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Cellulose molecules A cellulose molecule is an unbranched glucose polymer.
35
• Selülozu sindirmek zordur – İnek’lerin midelerinde bu işlemi kolaylaştıracak mikroplar bulunur
Figure 5.9
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• Kitin (diğer önemli polisakkarit) – Eklem bacaklıların dış iskeleti – Ameliyat ipi – Azot yan grubu H OH CH 2 O H H O OH H H NH C O CH 3 (a) The structure of the chitin monomer.
Figure 5.9 A–C
(b) Chitin forms the exoskeleton of arthropods. This cicada is molting, shedding its old exoskeleton and emerging in adult form. (c) Chitin is used to make a strong and flexible surgical thread that decomposes after the wound or incision heals.
37 Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Lipidler
• Hidrofobik • Polimer içermeyen büyük biyolojik molekül • Yağ • Fosfolipit • Steroid Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 38
Yağlar
– – İki tip küçük molekül, bir gliserol ve genelde üç yağ asidi Ester bağı Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 39
• Doymuş yağ asitleri – mümkün olan maksimum hidrojen – çift bağ yok
Figure 5.11
(a) Saturated fat and fatty acid
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Stearic acid 40
• Doymamış yağ asidi – Bir veya birden fazla çift bağ – Çift bağ olan herbir karbonda bir hidrojen eksik Oleic acid
Figure 5.11
(b) Unsaturated fat and fatty acid
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings cis double bond causes bending 41
• Fosfolipidler – Sadece iki yağ asidi – Üçüncü yağ asidi yerine fosfat bulunur Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 42
• Fosfolipitlerin yapısı – Sulu ortamda oluşan hücre membranındaki çift tabakalı yapı WATER Hydrophilic head Hydrophobic tail
Figür 5.13
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings WATER 43
Steroidler
• Birbirleriyle kaynaşmış dört adet halka içeren karbon iskeleti – Kolestrol – Eşey hormonları 44 Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• Kolestrol – hücre membranında bulunur – bazı hormonların öncüsüdür H 3 C CH 3 CH 3
Figür 5.14
HO Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings CH 3 CH 3 45
Proteinler
• Proteinler çeşitli fonksiyon lara neden olan farklı yapı lara sahiptir • Enzim • Hücrelerde çeşitli görev • Monomer; amino asit 46 Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• Protein görevlerine genel bakış Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 47
• Enzimler – Katalist (kimysal reaksiyonları hızlandırıcı) olarak görev yapan proteinler
1
Active site is available for a molecule of substrate, the reactant on which the enzyme acts.
Substrate (sucrose)
22
Substrate binds to enzyme. Glucose
OH H
O Fructose Enzyme (sucrase)
H 2 O 4
Products are released.
Figure 5.15
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
3
Substrate is converted to products. 48
Polipeptid
• Polipeptid – a.a oluşmuş polimer (zincir) • protein – Bir veya birden fazla polipeptid içerebilir 49 Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• Amino acid – Karboksil (C terminal) ve amino (N terminal) gr upları içeren organik molekül – R gr up (yan zincir) farklı a.a.’leri oluşturur 50 Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Yirmi Amino Asid
•
Nonpolar
20 different amino acids make up proteins CH CH 3 CH 3 CH 3 CH 3 H CH 3 H 3 N + C C H Glycine (Gly) O O – H 3 N + C C H Alanine (Ala) O O – H 3 N + CH 3 C C H Valine (Val) O O – H 3 N + CH 2 C C H Leucine (Leu) O O – CH 3 CH 2 H 3 C H 3 N + CH C C O H Isoleucine (Ile) O – CH 3 S CH 2 CH 2 O H 3 N + C C H O Methionine (Met) – CH 2 O H 3 N + C C H O – Phenylalanine (Phe) NH CH 2 O H 3 N + C C H O Tryptophan (Trp) – H 2 C H 2 N CH 2 CH 2 C C H O O – Proline (Pro)
Figure 5.16
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Polar Electrically charged
H 3 N + OH CH 2 C C H O O – H 3 N + OH CH 3 CH C C H O O – H 3 N + OH SH CH 2 C C H O O – H 3 N + CH 2 C C H Tyrosine (Tyr) O O – NH 2 C O NH 2 C O CH 2 H 3 N + CH 2 C C O H O – Asparagine (Asn) H 3 N + CH 2 C H (Gln) C Glutamine O O – H 3 N + – O C O CH 2 C C O O – H Aspartic acid (Asp) Acidic H 3 N + O – C O CH 2 CH 2 C C H O O – Glutamic acid (Glu) Basic H 3 N + NH 3 + CH 2 CH 2 CH 2 CH 2 C C H O O – Lysine (Lys) NH 2 C NH 2 + CH 2 CH 2 CH 2 H 3 N + CH 2 C C O H O – Arginine (Arg) H 3 N + NH + NH CH 2 C C O H O – Histidine (His) 52 Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Amino Asid Polimerleri
• Amino asidler – Peptid bağlarıyla bağlanırlar Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 53
Protein konformasyonu ve Fonksiyonu
• Bir protein’in spesifik konformasyonu (şekil) onun ne işe yarayacığına (fonksiyon) karar verir 54 Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Protein yapısındaki dört seviye
• Birincil yapı (Primary structure) – a .a.’lerin polipeptid yapısında oluşturduğu eşsiz (spesifik) düzenlenme Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings + H 3 N Amino end GlyProThrGly Thr Gly Leu Pro Val Lys Met Cys Lys Seu Glu Val Leu Asp AlaValArgGly Pro Ala Amino acid subunits
Figure 5.20
GluLle Asp Thr Lys Gly Leu Ala Lys Trp Tyr lle SerProPheHis GluHis Ala Asn Ala Thr Phe Val Val Glu Asp Ser GlyPro Arg ArgTyr Thr lle Ala Ala Leu Pro Leu Ser Thr Ser Tyr Ser Thr Ala Val Val ThrAsnProLys Glu c o o – Carboxyl end 55
• İkincil yapı (Secondary structure) – Polipeptid’de tekrar eden katlanma yada kıvrılmalar – helix ve pilili tabaka
pleated sheet
Amino acid subunits C N H O C H C R N H O O C R C H N H O C R C H N H O C R N H C R O C H C R C N H H O C R N H H C R C O C N H H N H O C C O C H C N R H R R C C N O H H O H C H C R N C N H H H C O N H C R O C R C O C H N H O C R N H C H C O H H N O C R C C H
helix
H C R H N R C O C H N H O C R N H C H C O H H N O C R C H H C R N C O C R N H C H C O H N
Figure 5.20
C Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 56
• Üçüncül yapı (Tertiary structure) – Polipeptidin üç boyutlu yapısı – a.a’lerin ve R gruplarının etkileşimi CH O
Hyrdogen bond
2 2 HO C CH 2 H 3 C H 3 C CH CH CH 3 CH 3 CH 2 S S CH 2
Disulfide bridge
O CH 2 NH 3 + O Ionic bond C CH 2
Hydrophobic interactions and van der Waals interactions
Polypeptide backbone 57 Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• Dördüncül yapı (Quaternary structure) – Proteini oluşturan iki veya daha fazla polipeptid’in oluşturduğu yapı Polypeptide chain
Collagen
Chains Chains Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Iron Heme 58
Protein yapısına genel bakış
+ H 3 N Amino end Amino acid subunits helix Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 59
Orak hücre hastalığı: proteinin birincil yapısında olan basit bir değişim
• Orak hücre hastalığı – Hemoglabin proteininde bulunan bir a.a’in değişimi 60 Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Primary structure Secondary and tertiary structures Normal hemoglobin
Val His Leu Thr Pro Glul Glu 1 2 3 4 5 6 7 . . .
Sickle-cell hemoglobin Primary structure
Val His Leu Thr Pro Val Glu 1 2 3 4 5 6 7 . . .
subunit
Secondary and tertiary structures
subunit
Quaternary structure
Hemoglobin A
Quaternary structure
Function
Function Red blood cell shape
Molecules do not associate with one another, each carries oxygen.
Normal cells are full of individual hemoglobin molecules, each carrying oxygen
Figure 5.21
10 m
Red blood cell shape
10 m Exposed hydrophobic region Hemoglobin S Molecules interact with one another to crystallize into a fiber, capacity to carry oxygen is greatly reduced.
Fibers of abnormal hemoglobin deform cell into sickle shape.
61 Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Protein konforma syunu etkileyen faktörler
• Proteinin bulunduğu fiziksel ve kimyasal çevrenin durumu • sıcaklık, pH, tuz (denatürasyon) 62 Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
•
Denat ürasyon; potein’in doğal yapısını kaybetmesi
Denaturation
Normal protein
Figure 5.22
Renaturation
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Denatured protein 63
Protein-katlanma Problemleri
• Çoğu proteinler – Kararlı yapıya ulaşmadan önce birkaç ara basamaktan geçerler – Denat üre olmuş protein aktif olarak görev yapamaz – Sıcaklık ve pH’ta ani değişimler denatürasyona sebeb olur 64 Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Şaperoninler Proteinlerin düzgün katlanması için gerekli olan protein molekülleri Correctly folded protein Polypeptide Cap Hollow cylinder
Figure 5.23
Chaperonin
(fully assembled) 1 Steps of Chaperonin Action: An unfolded poly peptide enters the cylinder from one end. 2 The cap attaches, causing the cylinder to change shape in 3 such a way that it creates a hydrophilic environment for the folding of the polypeptide. The cap comes off, and the properly folded protein is released.
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Nucleik Asid
• Nucleik acid ler kalıtımsal bilgiyi taşır ve transfer eder • Gen – Kalıtımsal yapının ana ünitesi – Polipeptidlerdeki a.a’leri belirler – Nükleik asitlerden oluşur 66 Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Nukleik A sidlerin rolü
• İki nükleik asit – Deoxyribonucleic acid (DNA) – Ribonucleic acid (RNA) Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 67
Deoksiribon ükleik asid
• DNA – Genetik materyal – Kendini replike edebilir – Spesif proteinlerin sentezi için gerekli bilgileri taşır (RNA sentezi) – Hücrelerin çekirdeğinde 68 Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
DNA görevleri
– RNA sentezi (transkripsiyon) – RNA’dan protein sentezi (translasyon) DNA 1 Synthesis of mRNA in the nucleus mRNA NUCLEUS CYTOPLASM mRNA Ribosome 2 Movement of mRNA into cytoplasm via nuclear pore 3 Synthesis of protein
Figure 5.25
Polypeptide Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Amino acids 69
Nucleik Acid yapısı
• Nucleic acid – Polinükleotid denilen polimerler halinde bulunur
5’ end
5’C 3’C O O O
Figure 5.26 (a) Polynucleotide, or nucleic acid
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 5’C 3’C OH O
3’ end
70
• n ükleotid – Polinükleotid monomeri – Şeker + fosfat + azot içeren baz – Fosfodiester bağı Nucleoside Nitrogenous base O O P O O Phosphate group 5’C CH 2 O 3’C Pentose sugar
Figure 5.26
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
(b) Nucleotide
71
Nükleozid
Fosfat içermeyen nükleotid kısmıdır O N C NH 2 C N H Cytosine C CH CH
Nitrogenous bases
Pyrimidines O HN C C CH O C N H CH Thymine (in DNA) T 3 O HN C O C N H CH CH Uracil (in RNA) U N C HC N H C Adenine A NH 2 C N N CH Purines HC N C N H N Guanine G O C NH C NH 2
Pentose sugars
5 ” HOCH 2 O OH 4’ H H 1’ H 3’ OH 2’ H H
Deoxyribose (in DNA)
5 ” HOCH 2 4’ H H OH 3’ O OH H 2’ OH H 1’
Figure 5.26 ( c) Nükleozid kısımları
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N ükleotid Polimerleri
•
N ükleotid polimerleri
– bir nükleotidin (şekerinin) 3´ karbonundaki OH ile diğer nükleotidin 5´ karbonunda bulunan fosfat arasında oluşan fosfodiester bağı ile bağlanan nukleotidler 73 Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• DNA double helix (çift sarmal) – iki antiparalel n ükleotid dizisi 5’ end 3’ end A 3’ end Sugar-phosphate backbone Base pair (joined by hydrogen bonding) Old strands Nucleotide about to be added to a new strand 5’ end 3’ end
Figure 5.27
5’ end Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings New strands 3’ end 74
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings