Transcript Pengantar Biokimia Pertemuan 1

SEJARAH DAN PERKEMBANGAN
BIOKIMIA
HENDRA WIJAYA
WHAT IS BIOCHEMISTRY?
• Definition:
–
Webster’s dictionary: Bios = Greek, meaning “life” “The
chemistry of living organisms; the chemistry of the
processes incidental to, and characteristic of life.”
– WebNet dictionary: “Biochemistry is the organic
chemistry of compounds and processes occuring in
organisms; the effort to understand biology within the
context of chemistry.“
PENGERTIAN BIOKIMIA
BIOKIMIA : ilmu yang berhubungan dengan
berbagai molekul di dalam sel atau organisme
hidup sekaligus dengan reaksi kimianya.
BIOS CHEMIOS
HIDUP/HAYATI
BIOLOGI
KIMIA/SENYAWA
ORGANIK
KIMIA
ORGANIK
ILMU KIMIA HAYATI (BIOKIMIA)
TUJUAN DAN MANFAAT ILMU BIOKIMIA
TUJUAN :
• Menguraikan semua proses kimiawi pada sel hidup
MANFAAT :
• Kesejahteraan manusia dan pengembangan ilmu
pengetahuan
• Dapat dikatakan hampir semua ilmu kehidupan
berhubungan dengan Biokimia.
BIOCHEMISTRY CAN BE SUBDIVIDED THREE
PRINCIPAL AREAS
1. Structural chemistry
2. Metabolism
3. The chemistry of processes and substances that
store and transmit biological information
(molecular genetics)
ISSUES ADDRESSED BY BIOCHEMISTRY
1. What are the chemical and three-deminsional
structure of biomolecules?
2. How do biomolecules interact with each other?
3. How does the cell synthesize and degrade
biomolecules?
4. How is energy conserved and used by the cell?
5. What are the mechanisms for organizing
biomolecules and coordinating their activities?
6. How is genetic information stored, transmitted,
and expressed?
HISTORY OF BIOCHEMISTRY
1. First to reveal the chemical composition of living
organisms.
2. Then to identify the types of molecules found in
living organisms.
3. Then to understand how the biomolecules make
life to be life.
4. Recent work of biochemist : Biopolymer Structure &
Function, Metabolism, Genetic Information
SEJARAH BIOKIMIA
 Pertama, identifikasi unsur kimia penyusun mahluk hidup.
Unsur kimia utama
penyusun mahluk hidup
adalah bahan minor
penyusun kerak bumi
(kandungan utama 47% O,
28% Si, 7.9% Al, 4.5% Fe,
dan 3.5% Ca).
Enam unsur utama
penyusun sel hidup
adalah: C, H, N, O, P,
dan S.
99% penyusun sel adalah H, O, N, dan C
Unsur
Elektron
bebas
Jumlah Fraksi
H
1
2/3
O
2
1/4
N
3
1/70
SEJARAH BIOKIMIA
•
Kemudian, identifikasi tipe molekul yang ditemukan dalam mahluk hidup
• Asam Amino
• Nukleotida
• Karbohidrat
• Lipida
Sebagian besar unsur penyusun bahan hidup memiliki berat atom yang
rendah; H, O, N dan C adalah unsur dengan berat atom relatif paling
kecil yang masing-masing mampu membentuk ikatan tunggal, rangkap,
rangkap 3 dan rangkap 4.
Unsur dengan berat atom paling ringan
membentuk ikatan paling kuat
SEJARAH BIOKIMIA
 Selanjutnya memahami mekanisme biomolekul membuat mahluk hidup
menjadi hidup
Year
1944
Proteins were thought to
carry genetic information
1897
Miescher discovered DNA
1828
Interweaving of the
historical traditions
of biochemistry,
cell biology,
and genetics.
RELATIONSHIP BETWEEN BIOCHEMISTRY AND
OTHER SUBJECTS
1. Organic chemistry, which describes the properties of
biomolecules.
2. Biophysics, which applies the techniques of physics to
study the structures of biomolecules.
3. Medical research, which increasingly seeks to
understand disease states in molecular terms.
4. Nutrition, which has illuminated metabolism by
describing the dietary requirements for maintenance of
health.
RELATIONSHIP BETWEEN BIOCHEMISTRY AND
OTHER SUBJECTS
5. Microbiology, which has shown that single-celled
organisms and viruses are ideally suited for the
elucidation of many metabolic pathways and regulatory
mechanisms.
6. Physiology, which investigates life processes at the
tissue and organism levels.
7. Cell biology, which describes the biochemical division
of labor within a cell.
8. Genetics, which describes mechanisms that give a
particular cell or organism its biochemical identity.
BIOCHEMISTRY AND LIFE
1. The cell is the fundamental unit of life
2. Prokaryotes and eukaryotes
3. Eukaryotic cells
1. animal cells
2. plant cells (chloroplasts and cell walls)
BIOCHEMISTRY AND LIFE
• Cells are composed of:
– Small molecules
– Macromolecules
– organelles
STRUCTURAL HIERARCHY IN THE MOLECULAR
ORGANIZATION OF CELLS
BIOCHEMISTRY AND LIFE
Percent of Total Cell
Weight
Number of Types of
Each Molecules
Water
70
1
Inorganic ions
1
20
Sugars and precursors 3
200
Amino acids and
precursors
0.4
100
Nucleotides and
precursors
0.4
200
Lipids and precursors
2
50
Other small molecules
0.2
~200
Macromolecules
22
~5000
The Approximate Chemical Composition of Bacterial Cell
BIOCHEMISTRY AND LIFE
• Expect for water, most of the molecules found in
the cell are macromolecules, can be classified into
four different categories:
–
–
–
–
Lipids
Carbohydrates
Proteins
Nucleic acids
BIOCHEMISTRY AND LIFE
1. Lipids are primarily hydrocarbon structures
2. Carbohydrates, like lipids, contain a carbon
backbone, but they also contain many polar
hydroxyl (-OH) groups and therefore very
soluble in water.
3. Proteins are the most complex
macromolecules in the cell. They are
composed of linear polymers called
polypeptides, which contain amino acids
connected by peptide bonds.
LIPID STRUCTURE
CARBOHYDRATES STRUCTURE
BIOCHEMISTRY AND LIFE
• Each amino acid contains a central carbon
atom attached to four substituents
–
–
–
–
A carboxyl group
An amino group
A hydrogen atom
An R group
• Nucleic acids are the large macromolecules in
the cells. They are very long linear polymers,
called polynucleotides, composed of
nucleotides.
AMINO ACIDS STRUCTURES
BIOCHEMISTRY AND LIFE
• A nucleotide contains :
– A five-carbon sugar molecules
– One or more phosphate groups
– A nitrogenous base
• DNA: A, T, G, C
• RNA: A, U, G,C
DNA CONTAIN FOUR BASES
RNA
COVALENT STRUCTURE OF DNA
WATSON-CRICK BASE PAIRS
WATSON-CRICK BASE PAIRS
THE DOUBLE HELIX
BIOCHEMICAL ENERGY
• All cellular functions re quire energy.
• The most-important chemical form of energy in
most cells is ATP, adenosine 5’-triphosphate.
• ATP
ADP + Pi
• Most ATP synthesis occurs in chloroplasts and
mitochondria
ADP AND ATP STRUCTURES
ENERGY TRANSFER
ENERGY TRANSFER
Transfer of Information from DNA to Protein
DNA
RNA
Protein
TRANSFER OF INFORMATION FROM DNA TO
PROTEIN