Protein Synthesis In Cytoplasm? 7 Facts You Should Know

Ribosomes, which are ribonucleoprotein particles, are responsible for protein synthesis in the cytoplasm. Let us understand the process in details.

Cytoplasm is where protein synthesis happens. DNA, RNA and several enzymes are used in the production of protein by cells. Typically, it encompasses transcription, translation, and post-translational processes such as protein folding, modifications, and proteolysis.

Based on DNA’s genetic code, protein synthesis produces the proteins necessary for cells to function and have a defined structure.

Does protein synthesis occur in cytoplasm?

Translation is the procedure used to create new proteins. Let us see if protein synthesis occur in cytoplasm or not.

Protein synthesis occur in cytoplasm as ribosome is where protein synthesis takes place after the mRNA molecule exits the nucleus. Protein is created by reading the genetic instructions contained in the mRNA during translation.

Though it is generally agreed that protein synthesis takes place in the cytoplasm, the notion that translation may also happen in the nucleus has been passionately contested.

When does protein synthesis occur in cytoplasm?

The first phase of protein synthesis, that is transcription takes place in nucleus. Let us see when protein synthesis occur in cytoplasm.

Protein synthesis occur in cytoplasm when spliceosome removes the intervening introns from the pre-mRNA molecule during splicing. Following that, nuclear pores in the nucleus’ envelope allow the mature mRNA molecule to exit the nucleus and enter the cytoplasm.

What part of protein synthesis occurs in the cytoplasm?

Protein synthesis is the process of producing protein. Transcription and translation are two crucial steps in this process. Let us see which process occurs in cytoplasm.

The second part of protein synthesis that is translation occurs in the cytoplasm. Here, the tRNA get charged and the mRNA attached with the smaller sub unit of ribosome, following the process of elongation and termination protein is synthesized.

Protein synthesis from Wikimedia

After the process of translation, post-translation modification also occurs inside the cytoplasm. All these steps are needed for protein synthesis.

How does protein synthesis occur in cytoplasm?

Protein synthesis is a crucial biological activity that keeps cells operating. Let us see how this method works.

The following are the key processes in the production of proteins:

  • Transcription
  • Translation
  • Post-translation modification (PTM)


In terms of genomics, transcription is the process of turning a gene’s DNA sequence into an RNA copy. It involves three steps which are explained below:

  • Initiation- RNA polymerase adhered to a DNA promoter region.
  • Elongation- Complementary nucleotides are drawn to one strand of DNA by RNA pol, which lengthens the newly formed strand.
  • Termination – The Terminator area is where RNA pol stops working. And the mRNA that was created is released.


Amino acids are joined together during translation in a specific order in accordance with the guidelines laid out by the genetic code. It takes place in the cytoplasm.

The four stages of translation are as follows

  • Activation – The tRNA and amino acid are joined covalently.
  • Initiation – Initiation factors enable the small subunit of the ribosome to bind to the 5′ end of mRNA.
  • Elongation-. Next in line, an elongation factor, GTP, and the aminoacyl-tRNA attach to the ribosome.
  • Termination – the A site of the ribosome faces a stop codon.

Post-translation Modification ( PTM):

After translation and the creation of peptide bonds, a polypeptide chain is subjected to an enzyme process known as post-translational modification.

The different types of post translation modifications are listed below –

  • Phosphorylation- a biological process that involves phosphating an organic molecule. As two examples, phosphate can be added to glucose to create glucose monophosphate or to ADP to create ATP.
  • Glycosylation- In the process of being connected to another molecule’s hydroxyl or other functional group to create a glycoconjugate, a carbohydrate, also known as a glycosyl donor, undergoes a process known as glycosylation.
  • Ubiquitination- A post-translational change known as ubiquitination occurs when the ubiquitin protein is joined to a substrate protein.
  • Nitrosylation- Nitrosylation is the covalent attachment of a “nitrosyl” group to another, frequently organic, molecule.
  • Methylation- Methylation is the process of incorporating a methyl group into a substrate or exchanging an atom for one.
  • Acetylation- A chemical reaction known as acetylation involves replacing a hydrogen atom in an organic chemical molecule with an acetyl functional group.
  • Lipidation- Lipidation is the process of a lipid group covalently attaching to a peptide chain.
  • Proteolysis- Proteins can be broken down into smaller peptides or even into individual amino acid residues by a process called proteolysis, which is the hydrolysis of peptide bonds.

Why does protein synthesis occur in cytoplasm?

The second pillar of protein synthesis is translation, which takes place in the cytoplasm. Let us see why it occurs inside cytoplasm.

Protein synthesis occurs in cytoplasm because it contain ribosome and other essentials required for the process. After entering cytoplasm, mRNA attach with smaller subunit of ribosomes. The right amino acids are delivered to ribosome by tRNA molecules, which read the codon sequences in the mRNA.

Role of protein synthesis in cytoplasm:

The primary process by which amino acids are disposed of is protein synthesis. Let us understand the role of protein synthesis in cytoplasm.

Protein synthesis in cytoplasm is an essential process because it allows human body to produce proteins that are required to carry out essential tasks. Human body would not be able to produce hormones, enzymes, or even new muscles without protein synthesis.

How nucleus control protein synthesis in cytoplasm?

Nucleus is called the brain of the cell. It controls most of the activities of the cell. Let us understand how it controls protein synthesis in cytoplasm.

Nucleus controls protein synthesis in cytoplasm by two processes:

  • Replication – synthesis the copies of DNA
  • Transcription – produces mRNA strand complementary to the DNA template.
  • This mRNa strand is used in the process of translation in cytoplasm.
  • Thus nucleus control protein synthesis through mRNA .


The method through which cells produce protein is called protein synthesis. Ribosome in cytoplasm receives instructions from processed mRNA. Then tRNA transports appropriate sequence of amino acids to ribosome after reading instructions in mRNA during translation. The completed protein may be created by further processing a polypeptide chain after it has been created.

Sadiqua Noor

Hi...I am Sadiqua Noor, done Postgraduation in Biotechnology, my area of interest is molecular biology and genetics, apart from these I have a keen interest in scientific article writing in simpler words so that the people from non-science backgrounds can also understand the beauty and gifts of science. I have 5 years of experience as a tutor. Let's connect through LinkedIn-

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