Protein Synthesis: Turning DNA into Life Through mRNA

The blueprint of all life can be attributed to DNA. Deoxyribonucleic acid (DNA), stores genetic information needed for the functioning and development of life (Bates, 2024). The DNA consists of a genetic code and the uniqueness of each individual’s code ensures continuity and change. These codes also act as instructions to synthesize proteins which perform essential roles in the body including acting as enzymes and catalysts (Northwestern.edu, 2016). Hence in protein synthesis, genetic information flows in a particular direction as existing DNA is replicated to form new DNA which is transcribed to form RNA and finally translated into specific proteins (Your Genome, n.d.).

(GeeksforGeeks)

DNA to mRNA- Transcription 

Step one of protein synthesis occurs in the nucleus. The main enzyme used in this process is known as RNA Polymerase and this synthesizes a complementary RNA strand from a single stranded DNA. RNA polymerase is attached to the promoter region of DNA (Khan Academy, 2016). The DNA strand acts as a template for RNA polymerase to synthesize RNA. The DNA strand unwinds and the template strand,containing information to be copied, is read by the RNA polymerase. The polymerase adds RNA nucleotides,  creating sugar-phosphate bonds to form a continuous strand. The nitrogenous base cytosine complements with guanine while adenine bonds with uracil. The new RNA molecule formed as the enzyme moves along DNA is the mRNA. This process occurs in a 5’ to 3’ direction. 

After the gene has been transcribed, the mRNA is processed as the non-coding regions known as introns are removed and a 5’ cap and poly-A tail are attached to aim in recognition by ribosomes. The molecule is then transported to the cytoplasm for translation (Vijayakumar, 2020).

From mRNA to Protein - Translation

The next step in protein synthesis is translation and occurs in the cytoplasm at organelles called ribosomes. Codons are sets of three bases. The ribosomes read mRNA by their particular codons. As a result of the variety in codon arrangements, each code for a specific amino acid. The specific amino acid paired with each codon is transported through transport RNA (tRNA) which have anticodons that are complementary to the codons on mRNA. The amino acids form peptide bonds together and the growing chain forms a polypeptide, stopping as the ribosome reaches the stop codon. As the polypeptide folds into its functional 3D form, a protein is synthesized that can be utilized for various functions (Khan Academy, 2016).

(Khan Academy)

The Significance

Protein synthesis forms proteins which allow for proper cell function. Proteins have a variety of functions in the body such as acting as chemical messengers like the hormone insulin. Structural proteins like collagen provide support to tissues and additionally, proteins such as haemoglobin carry oxygen through the bloodstream to where needed in the body (Robb, 2022).

In short, proteins are crucial in the body as without them the cell cannot work efficiently, grow or respond properly to stimuli. Mistakes in synthesis can result in mutations in disease. For this reason, the continuity and change of life is dependent on various body systems working together to create specific and accurate sequences that result in proteins from the code of life—DNA.

Reference list

Bates, S. (2024). Deoxyribonucleic Acid (DNA). [online] www.genome.gov. Available at: https://www.genome.gov/genetics-glossary/Deoxyribonucleic-Acid-DNA.

Khan Academy (2016a). Overview of translation. [online] Khan Academy. Available at: https://www.khanacademy.org/science/ap-biology/gene-expression-and-regulation/translation/a/translation-overview.

Khan Academy (2016b). Transcription: an overview of DNA transcription. [online] Khan Academy. Available at: https://www.khanacademy.org/science/ap-biology/gene-expression-and-regulation/transcription-and-rna-processing/a/overview-of-transcription.

Northwestern.edu. (2016). UNRAVELING THE CODE OF LIFE | HELIX. [online] Available at: https://www.helix.northwestern.edu/2016/01/25/unraveling-the-code-of-life/ [Accessed 1 Jun. 2025].

Robb, A. (2022). Protein Synthesis | Definition, Purpose & Function. [online] Study.com. Available at: https://study.com/learn/lesson/protein-synthesis-overview-purpose.html.

Vijayakumar, A. (2020). Transcription of DNA - Stages - Processing. [online] 

TeachMePhysiology. Available at: https://teachmephysiology.com/biochemistry/protein-synthesis/dna-transcription/.

Your Genome (n.d.). How is DNA turned into protein? [online] www.yourgenome.org. Available at: https://www.yourgenome.org/theme/how-is-dna-turned-into-protein-the-central-dogma-of-molecular-biology/.