4_biomolekul - Msp.Ummi.ac.id

BIOMOLEKUL
BIOCHEMISTRY
Definition:
the study of the chemistry of life
“The basic goal of the science of biochemistry is to
determine how the collections of inanimate
molecules that constitute living organisms interact
with each other to maintain and perpetuate life.”
Lenhinger, Principles of Biochemistry
BIOCHEMISTRY
Focus:
1. Biological Structures
Interaction, organization and coordination of biomolecules
Chemical and 3D structures of biomolecules
Synthesis and degradation of biomolecules
2. Metabolism
Energy production, utilization and conservation
anabolism vs catabolism
3. Genetic Information
Transmission, expression and storage of genetic information
Biology and Chemistry
Background
Biology
Prokaryotes vs Eukaryotes
Organelle Functions
Chemistry
Bonds
• Biomolekul :
Senyawa2 kimia yg secara alami hanya dite-
mukan dlm tubuh organisme atau sisa organisme setelah mati
• Atom penyusun biomolekul : C,H,O,N,S,P
• Pembagian Biomolekul :
1. Biomolekul sederhana
* Monosakarida
* Asam amino
* Asam lemak
* Asam Nukleat
•
2. Makromolekul :
* Polisakarida
* Polipeptida
* Lemak/ Lipid
* Polinukleotida
• ORGANISME : tersusun dr senyawa organik &
inorganik
• ORGANIK : - protein
- karbohidrat
- lipid
- asam nukleat : DNA, RNA
• INORGANIK : * asam
* basa
* garam
* H2O
• MAKROMOLEKUL KEBANYAKAN MERUPAKAN
POLIMER
• Contoh : Protein
rangkaian asam amino
Polisakarida
rangkaian monosakarida
monomer
hidrolisis
sintesis
H2O
H2O
polimer
• SINTESIS :
ikatan yg menghubungkan 2 unit molekul
terbentuk dgn. lepasnya H+ dr 1 molekul
penyusun dan OH- dr molekul berikutnya
terbentuk H2O
• HIDROLISIS :
putusnya ikatan antar unit molekul
molekul H2O
masuknya
• BIOMOLEKUL dibagi menjadi 2 yaitu :
1. STRUKTURAL : penyusun jaringan/tubuh
organisme
Contoh : kolagen, keratin
2. FUNGSIONAL : untuk melaksanakan fungsi
fungsi kehidupan
Contoh : enzim, hormon, DNA, RNA, ATP
• KARBOHIDRAT
1. Monosakarida = gula sederhana
CnH2nOn
ALDOSA
KETOSA
C3 Triosa
Gliserosa
Dihidroksiaseton
C4 Tetrosa
Eritrosa
Eritrolusa
C5 Pentosa
Ribosa
Ribulosa
C6 Heksosa
Glukosa
Fruktosa
Monosakarida
Disakarida
• 2. Disakarida ( Cn(H2O)n-1
* Sukrosa : Glukosa + Fruktosa
* Laktosa : Glukosa + Galaktosa
* Maltosa : Glukosa + Glukosa
• 3. Oligosakarida : 2-6 monosakarida
• 4. Polisakarida : >> monosakarida
Contoh : tepung
dekstrin
glikogen
selulosa
polimer glukosa
• Tepung ( Amilum )
* rantai lurus : ikatan (1-4)α glikosidik
* sedikit rantai cabang : ikatan (1-6)α gliko
sidik
• Glikogen : - strukturnya sama dgn amilum
- rantai cabang lebih banyak
• Sellulosa :
* tidak dapat dicerna (pd mamalia, manusia)
* tidak bercabang
* ikatan (1-4) β glikosidik
Amilosa
Amilopektin
Struktur Amilum
Ikatan α 1,6 Glikosidik
Struktur Glikogen
Sellulosa
Perbedaan Ik. α 1,4 dgn Ik. Β 1,4 Glikosidik
• PROTEIN
* tersusun dari asam amino
asam amino dasar
untuk menyusun protein : 20
* dari 20 asam amino dasar, separuhnya tidak
dapat disintesis di dalam tubuh hewan & manusia
shg. hrs diperoleh dr makanan
essensial
H
R-C-COONH3+
asam amino
• ASAM AMINO PENYUSUN PROTEIN
Essensial
Non essensial
Arginin
Alanin
Histidin
Aspartat
Isoleusin
Asparagin
Leusin
Sistein
Metionin
Glutamat
Fenilalanin
Glutamin
Threonin
Serin
Triptofan
Tirosin
Valin
Prolin
• LIPID
* sekelompok senyawa heterogen yg berhubungan dgn asam lemak, sifatnya :
1. relatif tidak larut dlm air
2. larut dlm pelarut non polar : eter, kloroform,
benzen
• Macam2 lipid :
1. Lemak netral : TG = Triasilgliserol
Contoh : mentega/margarin, minyak goreng
Jaringan lemak terutama t.d. : T.G.
2. Fosfolipid
3. Kolesterol & steroid
Lipid individual
tidak termasuk makromolekul
1. Triasilgliserol (TG)
2. Kolesterol
3. Fosfolipid
• Kandungan energi : tinggi
• Sumber asam lemak essensial
• Sumber vitamin yg larut dlm lemak : A,D,E,K
• ASAM LEMAK : asam monokarboksilat
* rantai pendek ( atom C < 6 )
* rantai medium ( atom C 8 – 14 )
* rantai panjang ( atom C > 14 )
Secara biologis yg banyak biasanya : asam lemak
rantai lurus, jumlah atom C genap ( 16-20)
• Pemberian nama :
* gugus –COOH diberi nomor 1
atau
* gugus –COOH tanpa simbol, atom C disebelahnya :
Cα
β,γ dstnya
• Berdasarkan ikatan rangkap, asam lemak :
1. Asam lemak jenuh ( saturated )
- tidak ada ikatan rangkap
- mis. Asam palmitat
Asam stearat
C16
C18
- akhiran : … + anoat (-anoic)
- jika rantainya panjang, p.u. bersifat padat pd suhu
kamar
- Asam palmitat
C16 (C15H31COOH) /
CH3(CH2)14COOH = asam heksadekanoat =
hexadecanoic acid
• ASAM LEMAK TAK JENUH ( UNSATURATED )
* ≥ 1 ikatan rangkap
* akhiran : -enoat ( enoic )
* yg alami : umumnya berbentuk Cis (sis)
cair pd suhu kamar
* asam lemak tak jenuh banyak terdapat pd
minyak tumbuhan ( kec. Minyak kelapa yg
banyak mengandung asam lemak jenuh )
• TG ( TRIASILGLISEROL )
* t.d Gliserol dan asam lemak
dalam sel
p.u. jumlah atom C : 16/18 per molekul
asam lemak
O
O
CH2-O-C-R1
R2-C-O-C
O
CH2-O-C-R3
* Sifat T.G. t.u. ditentukan oleh asam lemak yg
dikandungnya
• PURIN & PIRIMIDIN
* Senyawa heterosiklik yg mengandung N atau
disebut BASA N : Basa purin : Adenin (A)
Guanin (G)
Basa pirimidin : Timin (T)
Sitosin (C)
Urasil (U)
* Nukleosida = Basa N + gula
* Nukleotida = Basa N + gula + fosfat
= nukleosida + fosfat
Basa
Ribonukleosida
RiboNukleotida
A=Adenin
Adenosin
Adenilat = AMP
G=Guanin
Guanosin
Guanilat = GMP
U=Urasil
Uridin
Uridilat = UMP
C=Sitosin
Sitidin
Sitidilat = CMP
Basa
Deoksiribonukleosida
Deoksiribonukleotida
A
Deoksiadenosin
Deoksiadenilat
G
Deoksiguanosin
Deoksiguanilat
T=timin
Deoksitimidin
Deoksitimidilat
C
Deoksisitidin
Deoksisitidilat
A----T
G-----C
• PERANAN NUKLEOTIDA :
1. Bahan baku DNA & RNA (polinukleotida)
2. ATP
bentuk energi yg utama
3. Nukleotida adenin merupakan komponen 3
koenzim utama : NAD , FAD , KoA
4. Nukleotida sbg regulator metabolik
Mis. cAMP ( mediator kerja bbrp hormon )
ATP ( mengubah aktivitas sejumlah enzim dgn
modifikasi kovalen )
Coenzymes (vitamines)
Amino acids
carbohydrate
hormones
nucleotides
Amino acids
lipids
22nd edition designed by Dr. Donald E. Nicholson
metabolism is categorized into
two types
• Catabolism (biodegradation): larger
molecules (nutrients and cell
constituents) are broken down (often via
exergonic reactions) to salvage (reuse)
their components or/and to generate
energy.
• Anabolism (biosynthesis): The generation
of biomolecules from simpler components
(often via endergonic reactions).
(Fuels)
Exergonic Oxidation
Biodegradation
Output of energy
Simpler
Metabolites
Complex
Metabolites
Input of energy
Endergonic Reduction
Biosynthesis
Major Roles of Metabolism
• Extract energy and reducing power from the
environment (photosynthesis and oxidative
degradation of nutrients).
• Generation (interconversion) of all the
biomolecules for a living organism.
Thus comes the term
“Dynamic Biochemistry”
(Fuels)
The role of Metabolism
Extract energy and reducing power
ATP: Energy currency
Also for mobility,
transport of nutrients
and so on.
Generate all biomolecules
Classification of organisms based
on trophic (“feed”) strategies
• Autotrophs—synthesize all cellular
components from simple inorganic
molecules (e.g, H2O, CO2, NH3, H2S).
• Heterotrophs—Derive energy from
oxidation of organic compounds (made by
autotrophs).
Metabolism in various living
organisms allow carbon, oxygen
and nitrogen to be cycled in the
biosphere.
The cycling of matter is driven by
the flow of energy in one direction
through the biosphere!
Metabolism allows the cycling of C/O
and the flow of energy in the biosphere
glucose
Producers
Consumers
H2O
Metabolism also
allows the cycling
of N in the biosphere
(NH4+)
NO3NO2-
General Features of Metabolism
• Occurs in specific cellular (tissue and organ) locations as a
series of enzyme-catalyzed linear, branched or circular
reactions, or pathways.
• Highly coupled and interconnected (“Every road leads to
Rome”).
• Highly regulated (often reciprocally) to achieve the best
economy (“Balanced supply and demand”).
• The number of reactions is large (over 1000), however, the
number of types of reactions is relatively small (what
happens in animal respiration happens in plant
photosynthesis).
• Well conserved during evolution: reflecting the unity of the
life phenomena (“what happens in bacteria happens in
General approaches for
studying metabolism
• Purification and Chemical characterization of
metabolites;
• Tracing the fates of certain biomolecules in
living subjects (via such chemical labels as
isotopes).
• Isolation of genetic mutants having genetic
defects.
• Identification and characterization of enzymes.
Issues for current and future
investigation on metabolism
• Continue to unveil new pathways and new regulation strategies of
metabolism.
• Studies on enzymes.
• Observation of metabolic processes in intact living organisms (e.g., in
the brains under various states)
• Metabolism differences among various organisms or various states of
the same organism (for diagnosing and treating such diseases as
cancer, infections of bacteria or viruses, obesity, etc; to understand
aging).
• Appropriate and inappropriate nutrition.
• Biotechnological application of knowledge learned from metabolic
studies in medicine, agriculture and industry.
•
Nobel Prizes in revealing the
Metabolism of living matter (1)
• 1907, Eduard Buchner: cell-free fermentation.
• 1922, Archibald B. Hill: production of heat in the muscle?; Otto
Meyerhof: fixed relationship between the consumption of oxygen
and the metabolism of lactic acid in the muscle.
• 1923, Frederick Grant Banting, John James Richard Macleod:
discovery of insulin.
• 1929, Arthur Harden, Hand von Euler-Chelpin: fermentation of
sugar and fermentative enzymes.
• 1929, Christiaan Eijkman: antineuritic vitamin; Sir Frederick
Gowland Hopkins: growth-stimulating vitamins.
• 1931, Otto Heinrich Warburg: nature and mode of action of the
respiratory enzyme.
Nobel Prizes in revealing the
Metabolism of living matter (2)
• 1934, George Hoyt Whipple, George Richards Minot, William Parry
Murphy: liver therapy in cases of anaemia.
• 1937, Albert Szent-Gyorgyi: biological combustion, vitamin C and
the catalysis of fumaric acid.
• 1943, Henrik Carl Peter Dam: discovery of vitamin K; Edward
Adelbert Doisy: chemical nature of vitamin K.
• 1947, Carl Cori and Gerty Cori: catalytic conversion of glycogen;
Bernardo Houssay: hormone of the anterior pituitary lobe in the
metabolism of sugar.
• 1950, Edward Calvin Kendall, Tadeus Reichstein,Philip Showalter
Hench: hormones of the adrenal cortex, their structure and
biological effects.
• 1953, Hans Krebs: citric acid cycle; Fritz Lipmann: role of coenzyme A in metabolism.
• 1955, Axel Hugo Theodor Theorell: nature and mode of action of
oxidation enzymes“.
Nobel Prizes in revealing the
Metabolism of living matter (3)
• 1961, Melvin Calvin: carbon dioxide assimilation in plants.
• 1964, Konrad Bloch, Feodor Lynen: cholesterol and fatty acid
metabolism.
• 1971, Earl W. Sutherland, Jr.: mechanisms of the action of
hormones.
• 1978, Peter Mitchell: chemiosmotic theory of biological energy
transfer.
• 1982, Sune K. Bergström, Bengt I. Samuelsson, John R. Vane:
prostaglandins and related biologically active substances.
• 1985. Michael S. Brown, Joseph L. Goldstein: regulation of
cholesterol metabolism.
Nobel Prizes in revealing the
Metabolism of living matter (4)
• 1988, Sir James W. Black, Gertrude B. Elion, George H.
Hitchings: principles for drug treatment.
• 1988, Johann Deisenhofer, Robert Huber, Hartmut
Michel: photosynthetic reaction centre.
• 1992, Edmond H. FischerEdwin G. Krebs: reversible
protein phosphorylation as a biological regulatory
mechanism.
• 1994, Alfred G. GilmanMartin Rodbell: G-proteins and
the role of these proteins in signal transduction in cells.
• 1997, Paul D. Boyer, John E .Walker: synthesis of ATP.
• 1998, Robert F. Furchgott, Louis J. Ignarro, Ferid
Murad: nitric oxide as a signalling molecule in the
cardiovascular system.