Do Bacteria Have Ribosomes? Facts you should Know!

In this article we are laying down the facts that supports the question “Do bacteria have ribosomes” with the detailed facts you should know.

Ribosome is one of the intercellular organelles found inside the living cells, they are also called macromolecule machines because their main biological function is to produce proteins from amino acids by a process known as ‘Translation” or protein synthesis.

Ribosomes are found and manufactured in the cytoplasm in case of bacterial cells, by the transcription of multiple gene operons for ribosome. In case of Eukaryotes the process of formation of ribosomes occurs in the nucleolus as well as in cell cytoplasm. Ribosomes is a complex of RNA and protein. It is composed of two subunits a small and a large one each has a characteristic shape. During translation multiple ribosomes come together and gets attached to a common mRNA strand, the structure forms is known as Polysome.

do bacteria have ribosomes
Labelled Ribosome structure Image from Wikipedia

Facts about Bacterial Ribosomes

  1. In Ribosomes, the prefix “rib” has been derived from RNA which is used to provide instruction for making proteins.
  2. There are two types of ribosomes 80S and 70S, which can be broken into smaller and a larger subunit.
  3. A single bacterial cell contains thousands of ribosomes, and sometimes the numbers may vary from hundreds to millions.
  4. Ribosomes are essential to produce proteins which are the building blocks of cells and participate in number of cellular processes like, damage repair and chemical processes.
  5. Ribosomes are special structures; their size varies between 20 and 30 nm.
  6. The ribosomes in bacteria consists of separate ribosomal RNA with small ribosomal subunit 70.
  7. Ribosomes are present in all the living cells present in the planet, including Prokaryotes, eukaryotes, plant cells and blood cells.
  8. Ribosomes are unique from other cell organelles as they do not have a protective covering and are found scattered in the cytoplasm and also found attached to the endoplasmic reticulum.
  9.  In 1974, three American cell biologists Christian de Duve, Albert Claude and George Emil Palade discovered Ribosomes in cytoplasm that are found in bound form with Endoplasmic reticulum membrane.
  10. Life is impossible without ribosomes as they are essential for the synthesis of proteins which are necessary to maintain life.
Ribosome Structure Image from Wikiwand

What is Bacterial Ribosome?

Ribosomes are small particles that are consists of RNA and associated proteins.  Ribosomes in bacteria contains two subunits with densities 50S and 30S. Ribosomes in bacteria are a hub of multiple proteins and several ribosomal RNA molecules (rRNA).

What is the structure of Bacterial Ribosome?

The ribosome is said to be the cytoplasmic nucleoprotein, with a mass of approximately 2.5MDa. They are generally consisting of two subunits a small (30S) and a large (50S) to form an intact 70S structure. The large subunit consists of a 5S RNA subunit, 23S RNA subunit and 31 proteins while the small subunit contains a 16S RNA subunit in bound form with 21 proteins.

Ribosome is of temporary existence; it is broken up and reused after the synthesis of a polypeptide chain.

What are the Functions of bacterial ribosomes?

The central function of the ribosomes is to synthesize proteins from amino acids. They are well known as protein factories which are microscopic present in almost all the cells. Proteins produced by the ribosomes carry out all the significant functions inside the living cells. The function of small subunit is to associate with the messenger RNA during the process of translation and decoding whereas the large subunit is the site where peptide bond is formed and it functions as peptidyl transferase center.

Ribosomes are said to be the complex molecular machinery, present in all the living cells and catalyzes two essential processes during translation, Peptidyl transfer and peptidyl hydrolysis.  

Where are ribosomes found in bacteria?

Ribosomes are cell organelles that are found in the Cytoplasm, Nuclear membrane, cell wall, endoplasmic reticulum. There are approximately 10,000 ribosomes found in a single bacterial cell. In bacteria ribosomes are found dispersed in the cytoplasm, where they carry out the protein synthesis.

Do bacteria always have ribosomes?

Yes, ribosomes are found in all type of cells from a multicellular organism to a single celled organism including prokaryotes such as bacteria. All living cells require ribosomes for the formation of different proteins in order to maintain their existence.

Do all bacteria have ribosomes?

Yes, all prokaryotic cells including bacteria contains well-functioning and freely distributed ribosomes in their cells. Ribosome is the most numerous structures found inside the bacterial cells. Proteins secreted by the ribosomes helps to carry out all the necessary functions. In case of any damage to the cells such as UV radiation, proteins that are involved in repairing are synthesized by the Ribosomes, without ribosomes DNA repair proteins would not be synthesized.

Do bacteria have 80s ribosomes?

Prokaryotic cells including Bacteria and archaebacteria, have 70S ribosomes, they are non-membrane bound organelles. 80S ribosome is found most commonly in the cytosol of Eukaryotic cells.

Do bacteria have 70s ribosomes?

Bacteria do have 70S ribosomes. They are referred as 70S based on the sedimentation rates during ultracentrifugation. Larger subunit sediments at 50S and the smaller one sediment at 30S and together they sediment at 70S here, the ‘S’ refers to the “Svedberg units”.

Do gram positive bacteria have ribosomes?

Yes, gram-positive bacteria do have 70S ribosomes. They are called Gram-positive because they give positive result during gram staining. They have a thick peptidoglycan layer which retains purple color.

Read more about Are Bacteria Photosynthetic?

Do gram negative bacteria have ribosomes?

Yes, gram negative bacteria do have 70S ribosomes. Gram-negative bacteria give negative result during gram staining and they have a thin peptidoglycan layer.


To conclude our post, we can state that “Ribosomes” are essential features in all living organisms and a single cell to maintain the living system and to sustain life on the Earth.

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