Protein Synthesis Process

Proteins are important organic compounds present in living organisms. They are essential in almost all cell functions, though a specific protein is involved in a particular function. Proteins are made up of long chains of amino acids, which are either arranged in a linear pattern or folded to form a complex structure. Based on the structural complexity, protein structure is classified into four types - primary, secondary, tertiary and quaternary. Also, the types of amino acids play a crucial role in determining the expression of genes.

Protein synthesis is a biological procedure performed by living cells to make proteins in a step-by-step manner. Many times, it is used to denote translation, which otherwise is a primary part in the protein synthesis process. When studied in detail, protein synthesis is very complex. The process itself begins with production of different amino acids, out of which some are derived from food sources. Let's take a brief look at the process of protein synthesis.

Protein Synthesis Process: Explained

Speaking about protein synthesis process, it comprises two major parts - transcription and translation. The process involves ribonucleic acid (RNA), deoxyribonucleic acid (DNA) and a set of enzymes. All types of ribonucleic acid, namely messenger ribonucleic acid (mRNA), ribosomal ribonucleic acid (rRNA) and transfer ribonucleic acid (tRNA) are required for protein synthesis. Refer to the following information to understand regarding the two parts in the protein synthesis process:

Transcription
Transcription is the first part in the process of protein synthesis. It takes place in the cell nucleus, where deoxyribonucleic acid (DNA) is housed in the chromosomes. As we all know, DNA is a double helix structure. From the two parallel strands, one acts as a template to produce mRNA. As an initiation step of transcription, RNA polymerase binds itself to a particular site (promoter region) in one of the DNA strands that will act as a template.

Following its attachment to DNA template strand, the polymerase enzyme synthesize a mRNA polymer under the direction of the template DNA. The mRNA strand continues to elongate until the polymerase reaches a 'terminator region' in the DNA template. Thus, DNA transcription encompasses three steps - initiation, elongation and termination. The newly transcribed mRNA is released by the polymerase enzyme, which is then migrated to the cytoplasm to complete protein synthesis process. Know more on DNA transcription.

Translation
The second primary part of protein synthesis process is translation. Contrary to transcription that occurs in nucleus, translation takes place in the cytoplasm of the cell. This part is initiated as soon as the transcribed mRNA enters the cytoplasm. The ribosomes present in the cytoplasm immediately attach to the mRNA at a specific site, called the start codon. An amino acyl tRNA also binds at the mRNA strand. This phase is called initiation.

As the ribosome moves along the mRNA strand, the amino acyl tRNA brings amino acid one by one. This particular stage is called elongation. At the termination phase, the ribosome reads the last codon of the mRNA strand. With this, ends the translation part and the polypeptide chain is released. Precisely speaking, in translation, the ribosomes and tRNA attach to the mRNA, which read the coded information present in the strand. Accordingly protein synthesis of a specific amino acid sequence takes place. Read more on DNA translation.

Overall, protein synthesis process involves transcription of DNA to mRNA, which is then translated into protein. Thus, we have seen the process of protein synthesis requires proper coordination of RNA, DNA, enzymes and ribosomes. And the step wise procedure of protein synthesis is also known as central dogma in molecular biology.