ORGANIC COMPOUNDS OF LIFE

Chemical compounds of living things are known as organic compounds because of their association with the organism. Organic compounds, which are compounds associated with life processes, is the subject of organic chemistry. Among the various types of organic compounds, four main categories were found in all living things: carbohydrates, proteins, and nucleic acids.
The four compounds have been discussed in my previous blog post entitled macromolecules. In a blog post ORGANIC COMPOUNDS OF LIFE I am talking about the biosynthesis of proteins.

Following is a discussion of protein biosynthesis

PROTEIN

Protein (the root of the Greek word protos meaning "most important") are complex organic compounds of high molecular weight which are polymers of amino acid monomers are connected to each other by peptide bonds. Protein molecules containing carbon, hydrogen, oxygen, nitrogen and sometimes sulfur and phosphorus.
Protein is one of the bio-macromolecules essential role in living things. Every cell in our body contains protein, including the skin, bones, muscles, nails, hair, saliva, blood, hormones, and enzymes. In most tissues of the body, protein is the second largest component of the water. An estimated 50% of the dry weight of cells in the liver tissue and consists of meat protein. While the woven around 20% fresh meat.
Protein is found in many kinds of food, ranging from nuts, seeds, meat, poultry, seafood, beef cattle, to dairy products. Fruits and vegetables provide little protein. The selection of protein sources should be wise, because a lot of high protein foods are also high in fat and cholesterol. The function of the protein itself can be broadly divided into two major groups, namely as a structural material and as a machine that works on the molecular level.
Several structural proteins, fibrous proteins, serves as a protective, for example, a and b-keratin found in skin, hair, and nails. While there are other structural proteins that function as an adhesive, such as collagen. Protein may play functions as a structural material because, like other polymers, proteins have long chains and may also undergo cross-linking and others. Additionally protein can also serve as a biocatalyst for the chemical reactions in the system of living things. This macromolecule metabolic control pathways and complex time to maintain the viability of an organism. A metabolic system would be disturbed if the biocatalyst who played in it were damaged.

PROTEIN SYNTHESIS

The stages in the synthesis of proteins, can be divided into two, namely transcription and translation. Both transcription and translation, each divided further divided into three phases, namely initiation, elongation, and termination.
Transcription
Transcription is the synthesis of RNA using DNA as a template. DNA serves as the architect who designed the pattern of proteins while RNA preparation will be the ambassador as the carrier of genetic information in the form of code or the genetic code codons.
RNA transcription results one is m RNA that would serve as a template protein. Will set up a series of bases of mRNA codons (3 bases is a series that co-exist on a single mRNA that encode amino acids). Genetic Message mRNA translated into a series of amino acids based on the genetic code.
• Things to know in the transcription process:
o Promoter site, is the starting point for the process of transcription in which promoter is a nucleotide sequence that is recognized by transcriptase / RNA polymerase enzyme and a stick and start the process of transcription. On the promoter encountered three important points relating to the process of transcription, namely:
- Initial cue point, an area that shows sigma factor. That tells us that there are pieces of DNA downstream to be transcribed busi
- The area of ​​attachment, found somewhere downstream area sticking transcriptase enzyme composed of seven base pairs of the consensus sequence are sometimes often called Pribnow box (base pairs AT) AT-rich ps bs easier denatured (easier to open the double helix strands) than ps bs GC.
- The starting point of transcription, DNA is first transcribed nucleotides into RNA nucleotides. At this sticking point transkripstase be closely associated with DNA and Ribonuleotide will get to pair up with thread mold. The starting point is usually (90%) is a base Purines
• The enzyme RNA polymerase, is often referred to as RNA transcriptase to distinguish RNA in charge Replikasi.Enzim process is often used as a model organism. This enzyme is composed of a complex structure (composed of + 15 subunit - subunit) called Holoenzim active. Holoenzim consists of the core enzyme and the factors σ (sigma).
- Enzymes core: catalyzes the synthesis of RNA
- Factor σ (sigma): Recognizing early signs transcription template DNA found on another thread.
- Sub units - sub-units are not united by covalent bonds but with the secondary bond
• Antisense (-) strand. DNA is a double strand in the transcription of the DNA thread would be a mold / template. Meanwhile, the other thread will be a companion thread (thread antipararel) for Print thread. Nucleotide sequences of RNA synthesized is anti-parallel thread to thread with thread mold or companion. Thread mold called Antisense strand (-). Threads that are not used as a mold called Antisense strand (+).
• Terminator. Nucleotide sequences of DNA which suggests that transcription must end. All the terminator on prokaryote containing polidrom series, just before the point of closing. Polidrom are two sets of couples mounted inverted nucleotide by nucleotide sequences are separated by a small distance. The point of the cover is AT base pairs. Terminator will produce RNA with structures at the ends form hairpin formed by the pair between nucleotides repeated antipararel reversed. Besides, it also formed thread / chain poly U. Thread hairpin serves to reduce speed or stop working before the end of the transcription transcriptase.
• Terminology / Stage transcription
o Initiation
o elongation
o Termination
1. Initiation
The process of attachment of RNA polymerase to the promoter complex site.
2. Elongation
After the initiation process subunit σ (sigma factor) will break away and RNA synthesis followed by Core enzymes (enzymes that do not contain a factor sigma) using thread mold towards 51-31 and requires four kinds of nucleosides (ribonukleosida 51trifosfat) are: r-ATP, r-CTP, GTP-r, r-UTP.
3. Termination
Transcription lasted until the invention of signs to stop. Signs that simple termination is part of a sequence of DNA bases called palidrome GC and followed by a section of DNA rich in AT bases. When the genome does not contain palidrome then use protein Rho termination.
 Translating
Translation is the process of translating the genetic code by tRNA to the amino acid sequence. Translations into three stages, namely initiation, elongation, and termination. All of these stages require protein factors which help the mRNA, tRNA, and the ribosome during translation. Initiation and elongation of the polypeptide chain also requires some energy. This energy is provided by GTP (guanosine triphosphat), a molecule similar to ATP.
1. Initiation
The initiation phase occurs when the three components, namely mRNA, a tRNA containing the first amino acid of the polypeptide, and the two ribosomal subunits. mRNA from the nucleus to the cytoplasm out in coming by the ribosome, and mRNA into the "gap" in the ribosome. When mRNAmasuk to the ribosome, the ribosome "reads" incoming codon. Readings were taken for each of three base sequence until completed. For the record ribosomes that comes to reading codons are usually not just one, but multiple ribosomes known as polisom form a series of similar skewers, where tusuknya is "mRNA" and the meat is "ribosomnya".
Thus, the codon reading can take place sequentially. When I read the ribosome codon (eg kodonnya AUG), tRNA anticodon UAC and carrying the amino acid methionine to come. tRNA into the ribosome gap. Ribosomes are here serves to facilitate the specific attachment between tRNA anticodon with mRNA codons during protein synthesis. Ribosomal subunits constructed by protein-protein and ribosomal RNA molecules.

2. Elongation
In the elongation phase of translation, amino acids are added one by one in the first amino acid (methionine). The ribosome continues to shift so that more incoming mRNA, codon II to read. For example, codon II UCA, which immediately translated by tRNA codons AGU means carrying the amino acid serine. In the ribosome, which first entered methionine coupled with serine dipeptide form.
The ribosome continues to shift, reading codons III. Suppose III GAG codon, immediately translated by the CUC anticodon carrying the amino acid glycine. tRNA into the ribosome. Coupled with the amino acid glycine dipeptide that has been formed to form tripeptida. So forth the process of reading the genetic code took place in the ribosome, which translates into a form of amino acids to be assembled into a polypeptide.
MRNA codon on the ribosome to form hydrogen bonds with the anticodon of tRNA molecules had entered carrying the correct amino acid. MRNA molecules that have been releasing amino acids will return to the cytoplasm to reproduce the transport of amino acids. RRNA molecules of large ribosomal subunits function as enzymes, which catalyze the formation of peptide bonds that combine a polypeptide that extends to the newly arrived amino acids. 

   

3. Termination
The final stage is the translation termination. Elongation continues until the ribosome reaches a stop codon. Base triplet stop codons are UAA, UAG, and UGA. No stop codon codes for an amino acid but acts signal to stop translation. Polypeptides formed then "processed" into proteins.