Pp Ribosome

7/28/2019 Pp Ribosome

1/16

RIBOSOME AND PROTEIN

SYNTHESIS

By : Delfi Zurita

NIM : RSA1C411009


2/16

A.Definition Ribosome

Ribosomes are the components of cells that make proteins from all amino acids. Ribosomes also

referred to as molecular machines inside cells that make proteins from amino acids in a process called

translation, the ribosome "translates" the genetic information from RNA to protein. It binds messenger

ribonucleic acid (mRNA) and read the information contain in the mRNA nucleotide sequence.

The ribosome construct proteins from the genetic instructions held within messenger RNA.

Suspended free ribosomes in the cytosol (the semi-fluid cytoplasm), and the other attached to the rough

endoplasmic reticulum, thus giving the appearance of roughness, the other steps in the synthesis of proteins

(such as translocation) is caused by changes in protein conformation.


3/16

B. Structure of RibosomeRibosomes consist of ribonucleic acid (RNA abbreviated) and protein, in nearly equal numbers.

Ribonucleic acid derived from the nucleolus, where ribosomes are synthesized in the cell. A simple

prokaryotic cell (ex, bacteria) consisting of several thousands of ribosomes, while very advanced

eukaryotic cells (ex, human cells) have several millions of ribosomes. Prokaryotic ribosomes are smaller

in size compared to eukaryotic.

Beside, Ribosomes also consists of two parts, called subunits. Ribosomes size stated on the

basis of deposition rate during centrifugation as a unit called the Svedberg unit (S). In most prokaryotes

have 70S ribosomes size, where as in eukaryotes usually about 80S.Setiap subunit consists of both

protein and ribonucleic acid (RNA) components


4/16


5/16

Of the structure of the ribosome have the following properties:

1. The shape is universal, the elliptical longitudinal section.

2. On the negative staining technique, it appears that there is a transverse

groove, perpendicular to the axis, is divided into two sub-units that have

different dimensions.

3. Each sub-unit is characterized by a sedimentation coefficient expressed in

Svedberg units (S). So that the sedimentation coefficient of 70S for

prokaryotes is a whole ribosome (50S sub-unit for large and for small 30S).

For eukaryotic ribosome is 80S for the whole (60S to 40S subunits to large

and small).

4. The dimensions of the ribosome and the form of a variable. In prokaryotes,

the ribosome is 29 nm in length with a large 21 nm. And eukaryotes, a large

size of 32 nm with 22 nm.


6/16

5. In prokaryotes sub-units are small, elongated, curved shape with 2

limbs, features 3 digitized, like a chair. In eukaryotes, the subunits form

resemble the ribosomes of E. coli

On the surface of ribosomes, granular nucleoprotein has two

distribution layout. Nucleoprotein granules scattered freely in the

cytoplasm called a ribosome-free. Meanwhile, the nucleoprotein

granules attached to the surface of the endoplasmic reticulum called the

ribosome bound. Free ribosomes play a role in the synthesis of the

enzyme. Enzymes are produced serve as a catalyst in the liquid cytosol.

Ribosomes certainly be useful in the synthesis of proteins.


7/16


8/16

C. The Function of Ribosome

The function of the ribosome, they play assembling amino

acids to form specific proteins, which in turn is essential to carry out

the cell. As we all have a fair idea about the production of proteins,deoxyribonucleic acid (DNA) was first produced RNA (messenger

RNA or mRNA) by DNA transcription process, after which the

genetic message from the mRNA is translated into proteins during

translation of DNA.


9/16

D. The CompositionChemishtry of Ribosome

The composition of the ribosome is:

1. Ribosomal Nucleic Acid

a) large subunits composed of protein and RNA in the quantity of a balanced,

containing two types of rRNA, namely:

-The 28S rRNA

- The SS rRNA

b) small subunit-containing RNA 18s . It known that, in the absence of RNA 185, the

sub-unit can not associate small subunit. While the 28s RNA allows the association.SS RNA attached to the nucleic acid sequences are tRNA. When reading the tRNA

attached to the sites that are part of the RNA 285. Displacement of the tRNA molecule

attached to the mRNA causing translational motion of the corresponding mRNA.


10/16

2. Ribosomal Protein

a. Small subunit(30S prokaryotic): 21 proteins are described respectively by the

letter S and a number between 1 and 21 (S1, S2, S21). Weight moleku130.000 -

40,000 Dalton. Located on the surface of the ribosome, rRNA surrounds. Proteins

act as receptors for transducti elongation factor while the other controls.

b. Major subunit: 33 proteins known as Li to L33. Involved in Translocation by

the presence of GTP (ribosam attached) which provides energy to move the

release of tRNA and acetyl inRNA.


11/16

E. The Process ProteinSynthesis

Protein synthesis is the process of the formation of proteins in the cell, which

is inseparable from the role and workings of DNA that make up RNA through

RNA transcription process it will control the synthesis of proteins in the cell

cytoplasm.

Than Protein is a macromolecule composed by various amino acids, and enzymes

are proteins that act as catalysts for biochemical reactions in cell metabolism.

Enzymes characters (protein) as a control and the farmers mortal determined by

the number and type of amino acid sequence of the translated genes for protein

synthesis.


12/16

The components of protein synthesis

Components that play a role in protein synthesis is the cell nucleus, rough endoplasmic reticulum,

ribosomes rRNA, mRNA, tRNA, and RNA polymerase

a. The cell nucleus

Genetic cell nucleus resource location, namely DNA. So, the information is translated as the synthesis of

protein from the cell nucleus

b. RE rude and Ribosome (rRNA)

RE rough is the site where ribosomes attached. In addition, rRNA or site RNAmerupakan Ribosomal

protein synthesis

c. tRNA (transfer RNA)

tRNA is one type of RNA that serves to bind the amino acids from amino acids sitoplasmadan

combine with another at the stage of protein synthesis

d. RNA polymerase

RNA polymerase is an enzyme that plays a role in coupling DNA molecules and RNA molecules


13/16

Protein synthesis can be divided into two main phases, namely the process of

making mRNA molecules in the cell nucleus (transcription) and mRNA translation

process by coupling rRNA and amino acids (translation) ribosome

1. Transcription

Transcription occurs in the cell nucleus. In this phase, RNA polymerase chain adhere to

open-chain DNA. One of the DNA to be translated (DNA template / rantaisense) obtained

initiate partner base, so as to create the chain of complement. Complementary chain then

go into mRNA (messenger RNA).

2. Translation

Translation stage is the stage in which the mature mRNA from the nucleus of cells that

had been transferred to the cytoplasm, particularly in the ribosome, immediately

translated.Translation itself consists of three stages, is initiation, elongation and

termination


14/16

a. Initiation

At the mRNA reaches the ribosome, the first time that happened was initiation. Namely the

introduction of codons (3 couples code:. Ex UAA, AUG), which is a synthesis from beginnercodon (start codon), which is an amino acid Methionine, code-codon read After August, the

first amino acid of ribosomes would be combined with an acid amino next. Free amino acids

in the cytoplasm and carried to the ribosome by transfer RNA or tRNA.

b. ElongationElongation is a continuation of the process of initiation. At this stage, the codons will keep

reading and tRNA will continue to bring amino acids to the ribosome as it is the extension to

mRNA.Pada codon, the ribosome will usually be in the position of aggregates or bundles.

Two ribosomal mRNA or more be attached to chain together so it looks like to assemble.

This phenomenon is called ribosomes that group polisom and its function is to accelerate the

process of protein synthesis.


15/16

c. Termination

Termination is the last of the translational process. This process begins when the codons are

read codons coding for termination of protein synthesis. Codon called a stop codon, which

consists of three codons are UAA, UAG, and UGA. When someone reads a codon, will

dismiss the process of releasing factor amino. Process acid synthesis termination chain ends

with the formation of chains of amino acids that are very long, or more commonly called a

polypeptide chain. The name is based on the bond between one amino acid with another

amino acid called peptide bonds. Polypeptide chain is what we call a protein, instead of the

primary. Protein or polypeptide chains of protein synthesis is the primary protein chain.

Protein has been modified for use in the body. The process modifications will be made in the

body after the transfer of Golgi reticulum endoplasm


16/16

Thanks For YoursAttention

Pp Ribosome

Documents

Transcript of Pp Ribosome