Download 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
Organizmaa
Figür 1.4
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• Organdan - Hücre - Moleküle
9 Organeller
1 µm
Cell
8 Hücre
Atoms
10 µm
7 Doku
50 µm
6 Organ
Figür 1.4
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
10 Moleküller
Hücreye yakın bir bakış
• Hücre
- yaşam için gerekli olan tüm aktivitelerin
gerçekleştiği, biyolojik organizasyonun en küçük seviyesi
Figür 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
• İki form hücre
PROKARYOTIC CELL
DNA
(no nucleus)
Membrane
Cytoplasm
– Ökaryotik
– Prokaryotik
Organelles
Nucleus (contains DNA)
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
1 µm
Yaşamın üç Domain’i
• Yaşam en üst seviyede 3 domain’den oluşur
– Bakteri
– Archaea
Prokaryotik canlılar
– Eukarya
Protista Bitki Mantar Hayvan
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
3 domain
Bacteria are the most diverse
4 µm
and widespread prokaryotes
and are now divided among multiple
kingdoms. Each of the rod-shaped
structures in this photo is a bacterial cell.
DOMAIN ARCHAEA
Figür 1.15
Many of the prokaryotes known
0.5 µm
as archaea live in Earth‘s
extreme environments, such as salty lakes
and boiling hot springs. Domain Archaea
includes multiple kingdoms. The photo
shows a colony composed of many cells.
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.
Kindom Fungi is defined in part by the
nutritional mode of its members, such
as this mushroom, which absorb
nutrientsafter decomposing organic
material.
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Kingdom Plantae consists of
multicellula eukaryotes that carry
out photosynthesis, the conversion
of light energy to food.
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
• Atomlar’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), H2O (2:1)
• Elemetlerinden farklı karakterlere sahip
+
Figür 2.3
Sodyum
Sodium
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Klor
Chloride
SodyumChloride
klörür
Sodium
Atom
• Maddenin en küçük
parçası
• Her elementin belirli atom
çeşidi var
Nötron
Proton
Elektron
?
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Kimyasal Bağ
• Kovalent
• İyonik
kuvvetli
• Zayıf Kimyasal Bağlar
• Hidrojen bağı
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Kovalent Bağ
Name
(molecular
formula)
Electronshell
diagram
(c) Water (H2O).
Two hydrogen
atoms and one
oxygen atom are
joined by covalent
bonds to produce a
molecule of water.
(d) Methane (CH4).
Four hydrogen
atoms can satisfy
the valence of
one carbon
atom, forming
methane.
Structural
formula
O
H
H
H
H
C
H
Figür 2.12
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
H
Spacefilling
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.
2
Each resulting ion has a completed
valence shell. An ionic bond can form
between the oppositely charged ions.
–
+
Na
Na
Sodium atom
(an uncharged
atom)
Cl
Cl
Chlorine atom
(an uncharged
atom)
Figür 2.15
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Na
Na+
Sodium on
(a cation)
Cl
Cl–
Chloride ion
(an anion)
Sodium chloride (NaCl)
Hidrojen Bağı (Zayıf)
H
Water
(H2O)
O
H
+
–
Ammonia
(NH3)
N
H
+
Figür 2.16
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
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.
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
Makromoleküller
– Küçük moleküllerden oluşan büyük moleküller
– Yapısal olarak kompleks
– Kovalent bağ
Figür 5.1
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
20
Makromoleküller
•Çoğu Makromolekül monomerlerden
oluşmuş polimerlerdir
• 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
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
22
Polimerlerin oluşumu ve parçalanması
• Monomerler dehidrasyon tepkimesi ile daha
büyük molekülleri oluşturur
• H2O çıkışı
• Hidroksil (-OH) ve Hidrojen (-H) grubu
HO
1
2
3
H
Unlinked monomer
Short polymer
Dehydration removes a water
molecule, forming a new bond
HO
Figür 5.2a
1
2
H
HO
3
H 2O
4
H
Longer polymer
Dehydration reaction in the synthesis of a polymer
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
23
Polimerlerin oluşumu ve parçalanması
• Polimerler monomerlerine ortama H2O ilavesi
ile (Hidroliz) parçalanabilir
• -H bir monomere, -OH diğer monomere
HO
1
2
3
4
Hydrolysis adds a water
molecule, breaking a bond
HO
Figür 5.2b
1
2
3
H
H
H 2O
HO
H
Hydrolysis of a polymer
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
24
Karbohidratlar
• Şeker ve bunların polimerlerini
(nişasta, selüloz) içerir
• Monosakkaritler en basit şeker
• İki mososakkarit+kovalent bağ=
Disakkarit
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
25
• Örnek monosakkaritler
Triose sugars
(C3H6O3)
H
Aldoses
C
O
Pentose sugars
(C5H10O5)
H
O
H
C
H
O
C
C
H
C
OH
H
C
OH
H
C
OH
H
C
OH
H
C
OH
HO
C
H
C
OH
H
H
C
OH
H
Glyceraldehyde
H
Ribose
H
H
H
C
OH
H
HO
C
H
C
OH
HO
C
H
H
C
OH
H
C
OH
H
C
OH
H
C
OH
H
H
Glucose
Galactose
H
C OH
C
O
H
C OH
C
O
O
C OH
H
C OH
HO
H
H
C OH
H
C OH
Dihydroxyacetone
H
C OH
H
C OH
H
H
C OH
H
Figür5.3
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
O
H
H
C OH
C
Ketoses
Hexose sugars
(C6H12O6)
Ribulose
C H
H
Fructose
26
• Monosakkaritler
– Doğrusal (linear)
– Halkasal (ring)
H
H
HO
H
H
H
O
1C
2
6CH
C
OH
C
H
C
OH
3
4
5
C
6
C
OH
OH
2OH
5C
H
4C
OH 3
H
OH
C
H
6CH
O
H
H
1C
2C
OH
H
O
H
4C
OH
2OH
5C
H
OH
3C
H
CH2OH
O
H
H
1C
2C
OH
OH
6
H
5
4
HO
H
OH
3
H
O
H
1
2
OH
OH
H
Figür 5.4
(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.
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
27
• Disakkaritler
– İki monosakkarit
– Glikozidik bağ
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
28
Maltoz &Sükroz
(a) Dehydration reaction
in the synthesis of
maltose. The bonding
of two glucose units
forms maltose. The H
glycosidic link joins
the number 1 carbon
of one glucose to the HO
number 4 carbon of
the second glucose.
Joining the glucose
monomers in a
different way would
result in a different
disaccharide.
H
(b)
Dehydration reaction
H
in the synthesis of
O
sucrose. Sucrose is
a disaccharide formed
from glucose and fructose.
Notice that fructose,
though a hexose like
glucose, forms a
five-sided ring.
CH2OH
CH2OH
O
H
OH H
H
H
H
OH
HO
H
OH
H 2O
H
O
H
Glucose
CH2OH
H
O
H
HO
H 2O
O
H
H
OHOH
O
H
O
H
H
H
HO
H
OH
CH2OH
H
1–4
1 glycosidic
linkage
H
HO
OH
H
Fructose
H
OH
OH
Maltose
H
H
4
O
CH2OH
O
O
H
O
H
H
H
OH
Glucose
Glucose
CH2O
H
O
H
O H
H
H
OH
CH2OH
CH2OH
H O
O
H
H
H
HO
H
1–2
H
glycosidic
1
linkage
O
CH2OH
O
2
H
H HO
CH2OH
OH H
OH
Sucrose
Figür 5.5
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
29
• Polisakkaritler
– Şeker polimeri
– Organizmada çeşitli rol
• Depo polisakkaritleri
• Yapısal polisakkaritler
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
30
Depo polisakkaritleri
Chloroplast
• Nişasta
Starch
– Glikoz
monomerlerinden
oluşan polimer
– Bitkilerde glikozun
depo edilmesini
sağlar
1 m
Amylose
– Plastid
Amylopectin
Figure 5.6 (a) Starch: a plant polysaccharide
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
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
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33
Selüloz&Nişasta
H
CH2OH
H
4
HO
H
OH
H
O
H
H
OH
OH
 glucose
O
C
H
C
OH
HO
C
H
H
C
OH
H
C
OH
H
C
OH
CH2OH
H
H
OH
4
HO
H
O
OH
H
1
H
OH
 glucose
(a)  and  glucose ring structures
CH2OH
CH2OH
O
HO
O
1
OH
O
4
O
4
1
OH
OH
OH
O
O
1
OH
CH2OH
CH2OH
O
4
1
OH
O
OH
OH
(b) Starch: 1– 4 linkage of  glucose monomers
CH2OH
O
HO
OH
OH
1
O
4
OH
Figure 5.7 A–C
OH
O
CH2OH
CH2OH
O
O
OH
OH
O
O
OH
(c) Cellulose: 1– 4 linkage of  glucose monomers
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
OH
OH
CH2OH
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
held together by hydrogen
bonds between hydroxyl
groups attached to carbon
atoms 3 and 6.
Figure 5.8
OH CH2OH
OH
CH2OH
O O
O O
OH
OH
OH
OH
O
O O
O O
O CH OH
OH
CH2OH
2
H
CH2OH
OH CH2OH
OH
O O
O O
OH
OH
OH
OH
O
O O
O O
O CH OH
OH
CH
2
2OH
H
CH2OH
OH
OH CH2OH
O O
O O
OH
OH
OH O
O OH
O O
O
O CH OH
OH
CH
2
2OH
H
 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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36
• Kitin (diğer önemli polisakkarit)
– Eklem bacaklıların dış iskeleti
– Ameliyat ipi
– Azot yan grubu
CH2O
H
O OH
H
H
OH H
OH
H
H
NH
C
O
CH3
(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.
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
(c) Chitin is used to make a
strong and flexible surgical
thread that decomposes after
the wound or incision heals.
37
Lipidler
• Hidrofobik
• Polimer içermeyen büyük biyolojik
molekül
• Yağ
• Fosfolipit
• Steroid
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38
Yağlar
– İki tip küçük molekül, bir gliserol ve genelde üç yağ
asidi
– Ester bağı
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39
• Doymuş yağ asitleri
– mümkün olan maksimum hidrojen
– çift bağ yok
Stearic acid
Figure 5.11 (a) Saturated fat and fatty acid
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
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
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42
• Fosfolipitlerin yapısı
– Sulu ortamda oluşan hücre membranındaki
çift tabakalı yapı
WATER
Hydrophilic
head
WATER
Hydrophobic
tail
Figür 5.13
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
43
Steroidler
• Birbirleriyle kaynaşmış dört adet halka içeren
karbon iskeleti
– Kolestrol
– Eşey hormonları
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
44
• Kolestrol
– hücre membranında bulunur
– bazı hormonların öncüsüdür
H 3C
CH3
CH3
CH3
CH3
Figür 5.14
HO
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45
Proteinler
• Proteinler çeşitli fonksiyonlara neden
olan farklı yapılara sahiptir
• Enzim
• Hücrelerde çeşitli görev
• Monomer; amino asit
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46
• Protein görevlerine genel bakış
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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)
2 Substrate binds to
enzyme.
Glucose
OH
Enzyme
(sucrase)
H 2O
Fructose
H 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
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49
• Amino acid
– Karboksil (C terminal) ve amino (N
terminal) grupları içeren organik molekül
– R grup (yan zincir) farklı a.a.’leri oluşturur
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50
Yirmi Amino Asid
• 20 different amino acids make up proteins
CH3
CH3
H
H3N+
C
CH3
O
H3N+
C
H
Glycine (Gly)
O–
C
H3N
C
H
+
O–
C
CH2
O
H3N
C
H
Valine (Val)
Alanine (Ala)
CH
CH3
CH3
O
CH3
CH3
C
+
O–
O
C
H
Leucine (Leu)
H3C
H3N
+
O–
CH2
CH
C
O
C
H
Isoleucine (Ile)
O–
Nonpolar
CH3
CH2
S
NH
CH2
CH2
H3N+
C
H
CH2
O
H3N+
C
O–
Methionine (Met)
C
H
C
O–
Phenylalanine (Phe)
Figure 5.16
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
CH2
O
H3N+
C
H
O
C
H2C
CH2
H2
N
C
O
C
H
O–
Tryptophan (Trp)
Proline (Pro)
51
O–
OH
OH
Polar
H3N
+
CH2
C
O
C
H
CH
H3N
O–
Serine (Ser)
C
+
O
C
H3N
O–
H
+
CH2
C
H
O
C
CH2
H3N
O–
C
+
O
C
H
Electrically
charged
H3N
+
C
+
O–
O–
O
NH3+
NH2
C
CH2
C
CH2
CH2
CH2
CH2
CH2
CH2
O
H
O–
H3N
+
CH2
C
O
C
H
O–
H3N
+
CH2
C
H
Aspartic acid
(Asp)
O–
+
CH2
C
O
C
H
O–
Glutamine
(Gln)
Asparagine
(Asn)
C
C
C
H3N
Basic
O
C
CH2
O
H
Acidic
–O
CH2
H3N
Tyrosine
(Tyr)
Cysteine
(Cys)
Threonine (Thr)
C
NH2 O
C
SH
CH3
OH
NH2 O
Glutamic acid
(Glu)
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
O–
Lysine (Lys)
NH2+
H3N
+
CH2
O
C
NH+
H3N
+
CH2
C
H
NH
CH2
O
C C
O–
H
O
C
O–
Arginine (Arg)
Histidine (His)
52
Amino Asid Polimerleri
• Amino asidler
– Peptid bağlarıyla bağlanırlar
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53
Protein konformasyonu ve Fonksiyonu
• Bir protein’in spesifik konformasyonu (şekil)
onun ne işe yarayacığına (fonksiyon) karar
verir
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54
Protein yapısındaki dört seviye
• Birincil yapı
+H
3N
Amino
end
Amino
acid
subunits
Gly ProThrGly
Thr
Gly
Glu
Cys LysSeu
LeuPro
Met
Val
Lys
Val
Leu
Asp
AlaVal ArgGly
Ser
Pro
Ala
(Primary structure)
– a.a.’lerin polipeptid
yapısında oluşturduğu
eşsiz (spesifik)
düzenlenme
Glu Lle
Leu Ala
Gly
Asp
Thr
Lys
Ser
LysTrpTyr
lle
Ser
Pro Phe
His Glu
AlaThrPhe Val
Asn
His
Ala
Glu
Val
Thr
Asp
Tyr
Arg
Ser
Arg
Gly Pro
lle
Ala
Ala
Leu
Leu
Ser
Pro
SerTyr
Tyr
Ser
Thr
Thr
Ala
Val
Val
Glu
Thr Pro Lys
Asn
Figure 5.20
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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
O H H
C C N
C N
H
R
R
C C N
O H H
C
C
R
N H
C
H
R
O C
O C
N H
N H
N H
O C
O C
H C R H C R
H C R H C
R
N H O C
N H
O C
O C
H
C
O
N H
N
C
C
H
R
R H
C
R
R
O H H
C C N
C C N
OH H
R
R
R
O
O H H
C C N
O
H
O H H
C C N
C C N
OH H
R
O
C
H
H
N HC N H C N H C N
C
H
H
C
O
C
O
R
R
C
R
O
C
H
H
NH C N
C
H
O C
R
R
C C
O
R
H
C
N HC N
H
O C
H
 helix
Figure 5.20
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56
• Üçüncül yapı (Tertiary structure)
– Polipeptidin üç boyutlu yapısı
– a.a’lerin ve R gruplarının etkileşimi
CH22
CH
O
H
Hyrdogen
O
bond
H 3C
CH
CH3
H 3C
CH3
CH
Hydrophobic
interactions and
van der Waals
interactions
Polypeptide
backbone
HO C
CH2
CH2 S S CH2
Disulfide bridge
O
CH2 NH3+-O C CH2
Ionic bond
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57
• Dördüncül yapı (Quaternary structure)
– Proteini oluşturan iki veya daha fazla
polipeptid’in oluşturduğu yapı
Polypeptide
chain
Collagen
 Chains
Iron
Heme
 Chains
Hemoglobin
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58
Protein yapısına genel bakış
+H
3N
Amino end
Amino acid
subunits
helix
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59
Orak-hücre hastalığı: proteinin birincil
yapısında olan basit bir değişim
• Orak-hücre hastalığı
– Hemoglabin proteininde bulunan
bir a.a’in değişimi
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60
Normal hemoglobin
Primary
structure
Val
His Leu Thr Pro Glul Glu
1 2 3 4 5 6 7
Secondary
and tertiary
structures
Quaternary Hemoglobin A
structure
Function
Sickle-cell hemoglobin
...
Primary Val His Leu Thr Pro Val Glu . . .
structure 1 2 3 4 5 6 7
 subunit


Molecules do
not associate
with one
another, each
carries oxygen.
Red blood Normal cells are
cell shape full of individual
hemoglobin
molecules, each
carrying oxygen
Figure 5.21


Secondary
and tertiary
structures
Quaternary 
structure

Function
10 m
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Exposed
hydrophobic
region
 subunit


10 m
Hemoglobin S
Molecules
interact with
one another to
crystallize into a
fiber, capacity
to carry oxygen
is greatly
reduced.
Red blood
cell shape
Fibers of
abnormal
hemoglobin
deform cell into
sickle shape.
61
Protein konformasyunu etkileyen faktörler
• Proteinin bulunduğu fiziksel ve
kimyasal çevrenin durumu
• sıcaklık, pH, tuz (denatürasyon)
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62
• Denatürasyon; potein’in doğal
yapısını kaybetmesi
Denaturation
Normal protein
Figure 5.22
Denatured protein
Renaturation
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63
Protein-katlanma Problemleri
• Çoğu proteinler
– Kararlı yapıya ulaşmadan önce birkaç
ara basamaktan geçerler
– Denatüre olmuş protein aktif olarak
görev yapamaz
– Sıcaklık ve pH’ta ani değişimler
denatürasyona sebeb olur
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64
Şaperoninler
Proteinlerin düzgün katlanması için gerekli olan
protein molekülleri
Polypeptide
Cap
Correctly
folded
protein
Hollow
cylinder
Chaperonin
(fully assembled)
1
Figure 5.23
The cap attaches, causing
Steps of Chaperonin
2
3
Action: the cylinder to change shape
in
An unfolded polysuch a way that it creates a
peptide enters the
hydrophilic environment for
cylinder from one
end. the folding of the polypeptide.
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
The cap comes
off, and the
properly
folded protein is
released.
65
Nucleik Asid
• Nucleik acidler kalıtımsal bilgiyi taşır
ve transfer eder
• Gen
– Kalıtımsal yapının ana ünitesi
– Polipeptidlerdeki a.a’leri belirler
– Nükleik asitlerden oluşur
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66
Nukleik Asidlerin rolü
• İki nükleik asit
– Deoxyribonucleic acid (DNA)
– Ribonucleic acid (RNA)
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Deoksiribonükleik asid
• DNA
– Genetik materyal
– Kendini replike edebilir
– Spesif proteinlerin sentezi için gerekli
bilgileri taşır (RNA sentezi)
– Hücrelerin çekirdeğinde
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68
DNA görevleri
– RNA sentezi (transkripsiyon)
– RNA’dan protein sentezi (translasyon)
DNA
1 Synthesis of
mRNA in the nucleus
NUCLEUS
2 Movement of
mRNA into cytoplasm
via nuclear pore
mRNA
CYTOPLASM
mRNA
Ribosome
3 Synthesis
of protein
Figure 5.25
Polypeptide
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Amino
acids
69
Nucleik Acid yapısı
5’ end
• Nucleic acid
5’C
– Polinükleotid denilen
polimerler halinde bulunur
O
3’C
O
O
5’C
Figure 5.26
(a) Polynucleotide,
or nucleic acid
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O
3’C
OH
3’ end
70
• nükleotid
– Polinükleotid monomeri
– Şeker + fosfat + azot içeren baz
– Fosfodiester bağı
Nucleoside
Nitrogenous
base
O

O
P
5’C
O
CH2
O
O
Phosphate
group
Figure 5.26
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
(b) Nucleotide
3’C
Pentose
sugar
71
Nükleozid
Nitrogenous bases
Pyrimidines
NH2
C
N
Fosfat içermeyen
nükleotid kısmıdır
O
O
C
HN
CH
CH
N
H
C
O
Cytosine
C
C
N
H
CH3
C
CH
O
HN
C
O
C
CH
CH
CH
N
H
Uracil
(inRNA)
RNA)
Uracil (in
UU
Thymine (in DNA)
T
Purines
O
NH2
N
HC
C
C
N
H
Adenine
A
HOCH2
CH
N
OH
O
H
H
H
N
3’
2’
1’
H
H
OH
Deoxyribose (in DNA)
Figure 5.26
(c)
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N
C
HC
N
H
C
NH
C
N
NH2
Guanine
G
Pentose sugars
5”
4’
C
5”
HOCH2
H
H
4’
H
OH
O
3’
2’
1’
H
OH
OH
Ribose
Ribose (in
(in RNA)
RNA)
Nükleozid kısımları
72
Nükleotid Polimerleri
• Nükleotid polimerleri
–
bir nükleotidin (şekerinin) 3´ karbonundaki
-OH ile diğer nükleotidin 5´ karbonunda
bulunan fosfat arasında oluşan fosfodiester
bağı ile bağlanan nukleotidler
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• DNA double helix (çift sarmal)
– iki antiparalel nükleotid dizisi
3’ end
5’ end
Sugar-phosphate
backbone
Base pair (joined by
hydrogen bonding)
Old strands
A
3’
end
Nucleotide
about to be
added to a
new strand
5’ end
3’ end
Figure 5.27
5’ end
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New
strands
3’ end
74
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