PROTEIN

1
PROTEIN
2
A. PENGERTIAN PROTEIN

• PROTEIN BERASAL DARI BAHASA YUNANI PROTOS THAT
  MEAN THE PRIME IMPORTANCE
• ARTINYA TERUTAMA ATAU PENTING
• G. MULDER MENEMUKAN BAHWA
• SENYAWA INI DITEMUKAN PADA SEMUA
• ORGANISME HIDUP BAIK PADA TUMBUHAN
• MAUPUN HEWAN, MERUPAKAN KOMPONEN
• TERBESAR DALAM JARINGAN TUMBUHAN DAN
• TUBUH HEWAN

3
A. PENGERTIAN

• PROTEIN MERUPAKAN SENYAWA POLIPEPTIDA
• SETIAP PEPTIDA TERSUSUN ATAS ASAM AMINO SEBAGAI
  KOMPONEN TERKECIL
• UNSUR PENYUSUNNYA C,H,O,N

4
B. ASAM AMINO

• ASAM AMINO ADALAH SENYAWA YANG TERSUSUN ATAS
  GUGUS KARBOKSIL (COOH) DAN GUGUS AMIN (NH2)
• STRUKTUR
• H N C C OH

R
O
H
H
5
Structure of Amino Acid
The side group
H
O
O
C
H
C
N
H
H
H
H
Glycine The simplest amino acid
C
H
H
O
O
C
H
C
N
H
H
H
Alanine
6
CONDENSATION OF AMINO ACID
HOH
water

Amino acid
Amino acid
Dipeptida
An OH group from the acid end of one amino acid
and an H atom from the amino acid group of
another join to form a molecule of water
A peptida bond (highlighted in red) forms between
the two amino acids, creating a peptide
7
JENIS ASAM AMINO

• ASAM AMINO ESENSIAL (INDISPENSABLE AMINO ACID)
• ASAM AMINO YANG TIDAK DAPAT DISINTESIS
• OLEH TUBUH, HARUS DIPEROLEH DARI LUAR
  (MAKANAN)
• 2. ASAM AMINO NON ESENSIAL (DISPENSABLE AMINO
  ACID)
• ASAM AMINO YANG DAPAT DISINTESIS DI DALAM
  TUBUH, DARI SUPLAI NITROGEN
• 3. ASAM AMINO SEMI ESENSIAL (CONDITIONALLY
  ESSENSIAL)
• ASAM AMINO YANG PADA KONDISI TERTENTU TIDAK
  DAPAT DIBENTUK OLEH TUBUH

8
JENIS ASAM AMINO
ESENSIAL NON ESENSIAL SEMI ESENSIAL
Histidin Alanin
Lisin Arginin Arginin
Leusin Asparagin
Isoleusin Asam aspartat
Methionin Asam Glutamat
Valin Glutamin Glutamin
Threonin Glisin
Venilalanin Serin
Triptofan Prolin
Sistein Sistein
Tyrosin Tyrosin
9
C. FUNGSI

1. SUMBER ENERGI
2. MEMBENTUK STRUKTUR SEL
3. MEMBENTUK SISTEM PERTAHANAN TUBUH
4. MEMBENTUK SENYAWA TUBUH YANG ESENSIAL
5. KESEIMBANGAN ASAM BASA
6. KESEIMBANGAN CAIRAN TUBUH
7. TRANSPOR ZAT GIZI

10
1. SUMBER ENERGI

• PROTEIN DIGUNAKAN SEBAGAI SUMBER ENERGI BILA
  SUPLAI KARBOHIDRAT DAN LEMAK KURANG
• KARBOHIDRAT DAN LEMAK ADALAH PROTEIN-SPARING
• They spare amino acids from being burned for
  energy and allow them to be used for protein
  synthesis

11
2. MEMBENTUK STRUKTUR SEL

• SEL TERSUSUN ATAS PROTEIN
• FUNGSI PERTUMBUHAN DAN PEMELIHARAAN
• FUNGSI KOLAGEN YAITU SUATU PROTEIN FIBROUSA DI
  DALAM TUBUH YANG MEERUPAKAN KOMPONEN JARINGAN
  IKAT (CONNECTIVE TISSUE)

12
STRUCTURAL PROTEIN
PROTEIN PROVIDE STRUCTURE TO ALL CELLS
INCLUDING HAIR, NAILS, SKIN, AND BONE MOTOR
PROTEIN PROTEIN THAT TURN ENERGY
INTO MECHANICAL WORK. MOTOR PROTEIN ACTIVE IN
PROCESSES SUCH AS DIVIDING CELLS, CONTRACTING
MUSCLE, SWIMMING SPERM
13
3. SISTEM PERTAHANAN TUBUH

• PROTEIN MEMBENTUK ANTIBODY YANG BERTANGGUNG JAWAB
  UNTUK MELAWAN INFEKSI DAN BENDA ASING YANG MASUK
  DALAM TUBUH
• ANTIBODY PROTEIN YANG DIHASILKAN OLEH B
  LIMFOSIT SEBAGAI RESPON ADANYA ANTIGEN (PROTEIN
  PADA VIRUS ATAU BAKTERI)
• IMUNOGLOBULIN (Ig A, Ig E, Ig M) ADALAH PROTEIN

14
4. KESEIMBANGAN CAIRAN TUBUH

• PROTEIN DARAH DAPAT MENGHASILKAN TEKANAN ONKOTIK,
  YAITU TEKANAN UNTUK MEMPERTAHANKAN AGAR CAIRAN
  TUBUH TETAP BERADA PADA KOMPARTEMENNYA
• CAIRAN - INTRASEL DI DALAM SEL
• - EKSTRASEL a. INTERSELULER
• B.
  INTRAVASKULAR
• DEFISIENSI PROTEIN DI DALAM DARAH AKAN
  MENYEBABKAN ODEMA KARENA TEKANAN ONKOTIK YANG
  DIHASILKAN OLEH PROTEIN TIDAK MAMPU
  MEMPERTAHANKAN CAIRAN UNTUK TETAP BERADA DI DALAM
  KOMPARTEMEN, SEHINGGA CAIRAN AKAN KELUAR----ODEMA

15
Tekanan onkotik
Tekanan darah yang dihasilkan jandtung (tek.
Hidrostatik mendorong cairan keluar dari pembuluh
darah -----odema
Protein darah akan menarik cairan kedalam
16
5. MENGATUR ASAM BASA

• PROTEIN DARAH DAPAT BERPERAN SEBAGAI BUFER
• PH DARAH DITENTUKAN OLEH KONSENTRASI ION HIDROGEN
• SEMAKIN TINGGI KONSENTRASI ION H SEMAKIN RENDAH
  PH (SEMAKIN ASAM)
• ASAM PH lt 7

17
6. MEMBENTUK SENYAWA TUBUH ESENSIAL

• HORMON
• SUATU SENYAWA YANG DIHASILKAN OLEH TUBUH
  TERSUSUN ATAS PROTEIN UNTUK FUNGSI REGULATOR
• ENZIM
• ADALAH PROTEIN YANG MENGKATALIS REAKSI
  KIMIA DI DALAM TUBUH
• HEMOGLOBIN
• KOMPONEN DARAH YANG TERSUSUN ATAS PROTEIN
  DAN ZAT BESI

18
Human Insulin
Human insulin is relatively small protein that
consist of 51 amino acid in two short
Polypeptide chains. Two brigdes link he two
chains. A third bridge spans a section within
the short chain. Known as disulfide bridges,
these link involve the amino acid Cystein (Cys),
whose side group contains sulfur (S). Cystein
connect to each other when bonds form between
these side group.
19
7. TRANSPOR ZAT GIZI

• PROTEIN DI DALAM DARAH DAPAT BERPERAN PENGANGKUT
  ZAT GIZI LAINNYA
• CONTOH
• - RETINOL BINDING- PROTEIN (RBP)
• - TRANSFERIN
• - LIPOPROTEIN

20
D. DIGESTION AND ABSORPTION

• Digestion is facilitated mostly by the stomachs
  acid and enzymes, wich first denature dietary
  protein, then cleave them into smaller
  polypeptides and some amino acid.
• Pancreatic an dintestinal enzymes split this poly
  peptides further to oligo-, tri-,and dipeptides,
  and then split most of these to single amino
  acid.
• Then carries in the membranes of intestinal cells
  transport the amino acid into the cells, where
  they are releases into the bloodstream
• What happen in each organd on protein and HCl
  enzymes?

MOUTH
Salivary glands
stomach
esophagus
Pancreatic duct
liver
gallblader
pancreas
Small intestine
21
PENCERNAAN PROTEIN

• MULUT BELUM TERJADI PENCERNAAN
• LAMBUNG PROTEIN

PEPSIN
PEPTIDA
HCL
PANKREATIK PROTEASE PEPTIDASE
ASAM AMINO
USUS HALUS PEPTIDA
ALKALI
22
PENCERNAAN

• DI LAMBUNG
• Terjadi denaturasi protein oleh HCl, sehingga
  protein mudah dipecah oleh enzim
• Dinding lambung menghasilkan pro-enzim
  pepsinogen, yang diaktifkan oleh HCl menjadi
  enzim pepsin
• Pepsin sangat aktif pada pH 2,5 dan inactif pada
  pH gt5
• Sekresi cairan lambung pH 0,8 dan bila bercampur
  dengan makanan maka pH menjadi 2-2,5 menjadi pH
  yang ideal untuk mengaktifkan pepsin
• Pepsin bertanggung jawab 10-20 dari proses
  pencernaan

23
PENCERNAAN

• DI USUS HALUS
• Pemecahan protein terjadi secara efektif di usus
  halus
• Dinding usus dan pankreas menghasilkan pro-enzim
  tripsinogen dan kimotripsinogen sebagai respon
  masuknya protein di dalam usus, yang berubah
  menjadi enzim tripsin dan kimotripsin karena
  suasana alkali
• Enzim lainnya adalah peptidase memecah dipeptida
  menjadi asam amino

24
E. METABOLISME PROTEIN

• DALAM KONDISI NORMAL, HANYA HANYA 15 PROTEIN DI
  DALAM TUBUH YANG DIUBAH MENJADI ENERGI
• PROTEIN DI DALAM TUBUH MENGALAMI TURN OVER

25
METABOLISM

• The sum total of all the chamical reactions
  that go on in living cells
• Anabolism reaction in which small molecules are
  put together to build larger one.
• Anabolic reactions require energy
• Catabolism reactions in which large molecules
  are broken down to smaller one.
• Catabolic reaction release energy

26
PROTEIN SYNTHESIS

• Protein can be synthesized in the body cell
  (ribosome)
• Each human being is unique because of small
  differences in the bodys proteins., which in
  turn, are determined by genes.
• When a cell makes a protein, its called the gene
  for that protein has been expressed. Cells can
  regulate gene expression to make the type of
  protein.

27
PROTEIN TURN OVER AMINO ACID POOL

• Protein turn over
• Whitin each cell, protein are continually being
  made and broken
• When protein break down, they free amino acid
• These amino acid mix with amino acid from dietary
  protein form an amino acid pool within the
  cells and circulating blood

28
NITROGEN BALANCE

• In healthy adults, protein synthesis balance with
  degradation, and protein intake from foof
  balances with nitrogen excretion in the urine,
  feces and sweat.
• Nitrogen status is positive in growing infants,
  children, adolescents, pregnant women
• Nitrogen status is negative in people who are
  starving or suffering other severe stresses such
  as burn, injuries, infections, fever

29
JALUR METABOLISME PROTEIN
PROTEIN
KARBOHIDRAT
LEMAK
GLUKOSA
ASAM AMINO
GLISEROL
ASAM LEMAK
PIRUVAT
ACETYL Co A
TCA CYCLE
NH3
H2O
CO2
30
TURN OVER PROTEIN
Pemecahan AA Dari sell
DIETARY PROTEIN
Degradasi protein
BODY PROTEIN
ASAM AMINO
Sintensis protein
POOL AA DLM SEL
Sintesis senyawa Non protein
HATI Kel. AA Carbon
Urea
Asam Lemak
Glukosa
Energi
GINJAL
31
METABOLISME PROTEIN

• PROSES METABOLISME PROTEIN ADA 2 MACAM
• 1. PROSES TRANSAMINASI
• 2. PROSES DEAMINASI
• TRANSAMINASI
• PROSES PEMINDAHAN GUGUS AMIN DARI SATU ASAM
  AMINO UNTUK MEMBENTUK ASAM AMINO BARU
• CONTOH PEMBENTUKAN SISTIN DARI METIONIN
• DEAMINASI
• PROSES PENGHILANGAN GUGUS AMIN SEHINGGA AKAN
  MEMBENTUK SENYAWA BARU
• CONTOH PEMBENTUKAN NIASIN DARI TRIPTOFAN

32
DEAMINATION

• When amino acid are broken down (as occurs when
  they are used for energy), they are first
  deaminated, stripped of their amino groups.
• Deamination produce ammonia, which the cells
  release into the bloodstream.
• The liver pick up the ammonia, converts it into
  urea (a less toxic compound), and returns urea
  into the blood.
• The production of urea increase as dietary
  protein increase (max 250 g/day)

33

• Two products result from deamination
• 1. a keto acid (the carbon structure without
  
• amino group)
• 2. Ammonia (NH3), a toxic compound
• Most amino acids can be used to synthesize
  glucose from pyruvate, they are called a
  glucogenic amino acid
• Some amino acids are converted directly to acetyl
  CoA, they called ketogenic amino acid

34
AMINO ACID ENTER THE ENERGY PATHWAY
NH2
Glucogenic Amino acids
Piruvate
NH2
Coenzyme
CoA
To electron Transport chain
H
Coenzyme
E-
CO2
NH2
Ketogenic Amino acids
Acetyl CoA
NH2
TCA Cycle
Glucogenic Amino acids
NH2
35
TRANSAMINATION

• The transfer of an amino group from one amino
  acid to keto acid, producing a new non essential
  amino acid and a new keto acid
• Through many such transamination reactions,
  involving many different keto acids, the liver
  cells can synthesize the non essential amino
  acids

36
TRANSAMINATION
Side group
Side group
O
NH2

C
C
H
COOH
COOH
Keto acid A
Amino acid B
Side group
Side group

NH2
O
C
H
C
COOH
COOH
Keto acid B
Amino acid A
37
UREA EXCRETION The liver and kidneys both play a
role in Disposing of excess nitrogen. Person
with liver disease has high blood ammonia
Person with kidney disease has high blood urea
Blood stream
Amonia
(NH3)

CO2
Liver
Urea
Urea
Blood stream
Urea
Kidney
To blader out of body