Diagram of Ribosomes

Last Updated : 23 Jul, 2025

The ribosome diagram illustrates these cell organelles' structure, showcasing their role in protein synthesis within the cell. Ribosomes float freely in the cytoplasm. Each cell contains many ribosomes, made of RNA and protein molecules. The labeled diagram of ribosome reveals its components - the small and large subunits, mRNA binding site, and tRNA binding sites. The diagram of ribosome class 9 is often asked in the examinations and hence is important to cover.

The labeled diagram of ribosome is given below:

👁 Ribosome

Table of Content

What is a Ribosome?

Ribosomes are small, spherical organelles found floating in the cell cytoplasm or attached to membranes. The diagram of a ribosome shows the structure containing two subunits: a larger one and a smaller one which combine for protein synthesis. Ribosomes play a key role in cell growth, maintenance, and normal functions. They make proteins required for cellular processes.

Structure of Ribosomes

The diagram of ribosomes with labelling shows that it consists of the RNA component and the protein part. Ribosome has a larger subunit that joins with the smaller subunit.

Larger subunit

The larger part of ribosome contains ribosomal RNA and proteins.
It has 23S and 5S RNA molecules, along with many proteins.
This subunit works as a site for proteins synthesis during this process.

Smaller subunit

Ribosomes have a small subunit.
This small subunit contains the 16S rRNA molecule. It's also called the 30S subunit.
During translation initiation, it binds to mRNA (messenger RNA).

Also Read: RNA Translation

Functional Sites

Ribosomes has following functional sites:

A-site: The aminoacyl site binds tRNA during protein synthesis. It holds the tRNA carrying the next amino acid.
P-site: Called the peptidyl site, it elongates the polypeptide chain, It attaches new amino acid growing the protein.
E-site: Known as the exit site, it releases tRNAs,After giving up their amino acids, uncharged tRNAs leave here.

Ribosomal RNA (rRNA)

Ribosoma RNA plays a crucial role in ribosome structure and function
rRNA is first transcribed in the nucleus and then processed before assembly into ribosomes.

Types of Ribosomes

Based on its size and the sedimentation coefficient (S), ribosomes are categorized into two types:

70 S- found in prokaryotic cells
80 S- found in eukaryotic cells

Based on its location it is categorized into two types:

Free floating on the cells cytoplasm
Attached to endoplasmic reticulum,it is called as the rough endoplasmic reticulum

Also Read: Difference Between 70s and 80s Ribosomes

Conclusion - Diagram of Ribosomes

In conclusion, ribosomes play an extremely important part in protein synthesis. The labelled diagram of ribosome shows its detailed structure. Ribosomes are very important for cell growth, maintenance, and are essential in normal cell functions. Ribosomes are also responsible for producing proteins that are needed for cellular processes.