Do Plants Have Ribosomes?

Yes. Plants have ribosomes.

Plants and animal cells are eukaryotic cells that have all essential organelles. These include mitochondria, nuclei, ribosomes, etc. Besides floating freely like other organelles in the cell, ribosomes also attach to the endoplasmic reticulum (ER). The part of the endoplasmic reticulum with ribosomes is the rough endoplasmic reticulum.

Ribosomes are called the “Protein factory” of the cell as they synthesize proteins for all cellular and bodily processes. Let us tell you about ribosomes in plants in detail.

What Are Ribosomes In Plants?

Ribosomes are complex molecules in living cells that produce proteins through translation. They are present in the cytoplasm as free ribosomes besides the Rough ER. Ribosomes obtain information from the nucleus and produce proteins.

Structure of Ribosomes

Ribosomes look like small rocks composed of two units joined together. They are known as ribonucleoproteins as they comprise protein and RNA. RNA constitutes 62% of the total weight of ribosomes compared to proteins. A membrane may bind them. Yet, ribosomes are not membranous.

Prokaryotes and Eukaryotes have different sizes of ribosomal subunits per need. They have two subunits that make up a ribosome. Prokaryotes have the 70S composed of 50S larger and 30S smaller subunits. Alternatively, eukaryotes have 80S subunits based on 60S and 40S subunits. They are quite small in size, though. You can observe ribosomes under a microscope to understand their structure well.

The smaller subunit of the ribosome decodes the mRNA, and the larger subunit incorporates the amino acid. The two subunits join by interactions between protein and rRNA in either of them. 

Functions Of Ribosomes

Now that you know plants have ribosomes like animals, what do they do?

The main role of ribosomes includes assembling amino acids and converting them into proteins to carry out essential cellular functions. It happens in two steps.

  • The DNA is converted into mRNA through DNA transcription.
  • The ribosomal subunits bind around the mRNA polymers, and the tRNA produces proteins.

After the proteins are synthesized and utilized in the cytoplasm, the rest produced by bound ribosomes move outside the cell.

Protein synthesis is the most prominent function of ribosomes. Thus, ribosomes are essential for any organism’s everyday activities.

Other Functions Of Proteins In Plants

The proteins produced by ribosomes in plants help in structural, functional, and enzymatic roles. They facilitate transport, biosynthesis, photosynthesis, immunity, storage, and nutritional demands for developing seedlings. Proteins also regulate growth and development in plants.

Protein Synthesis Process

The process of protein synthesis by the ribosomes consists of three basic steps; Initiation, elongation, and termination. 

Initiation

A small ribosomal subunit links to the start end of an mRNA to initiate the process. Initiator tRNA also penetrates the smaller subunit. This subunit then combines with the larger ribosomal subunit. The coded message at the ‘start end’ of the mRNA initiates polypeptide production. The codon (three-letter code) in the tRNA must match the anti-codon on the ribosomal mRNA. The absence of a compatible codon will reject the tRNA and alter protein production.

Elongation

The next part of the process is elongation. The main part of the particular protein is synthesized during elongation. Translocation is among the main processes in elongation. It is the instance where the ribosome moves along the mRNA to begin a new cycle. The peptide chain elongates by the addition of amino acids. The process continues to produce longer peptide chains until it reaches termination.

Termination

Termination is the last step of the process, which shows that the protein is synthesized and the process must stop. A terminal message present at the end of the mRNA strand indicates that the protein code is complete. Release factors inhibit further addition of amino acids. The ribosomal units separate from each other. They are broken down or re-used per need.

Conclusion

Ribosomes are present in prokaryotic and eukaryotic cells, which means that plants also have ribosomes. Ribosomes are composed of two subunits and are quite small in size. They are known as the protein factory in living cells. You can observe ribosomes under an electron microscope. Proteins produced by ribosomes help plants in various structural, enzymatic, and functional roles. They regulate growth, act as food storage and meet the nutritional demands of budding seedlings.