The ribosome, a crucial enzyme for protein synthesis, consists of large and small subunits made primarily of ribosomal RNA (rRNA) and proteins. It features binding sites for transfer RNA (tRNA) and messenger RNA (mRNA), and functions in peptide synthesis by translating genetic code. Prokaryotic ribosomes are 70S, while eukaryotic ribosomes are 80S, with differing subunit compositions.

1. Ribosome
Presented by
Mr.Karthick J.

2. Ribosome
• The synthesis of proteins is catalyzed by
the ribosome.
• The ribosome is made up of a large and small
subunit, and is a large enzyme comprised
mostly of ribosomal RNA (rRNA), with
proteins.
• Besides the rRNA, the ribosome contains
binding sites for tRNA and mRNA.

3. • The rRNA forms most of the ribosomal
structure and performs the catalytic steps of
peptide synthesis, the mRNA delivers the
genetic message, and tRNA translates the
genetic code into peptide sequence.
• The ribosomal subunits of prokaryotes and
eukaryotes are quite similar.
• The unit of measurement is
the Svedberg unit, a measure of the rate
of sedimentation in centrifugation rather than
size.

4. STRUCTURE
• It has two sites ‘A’ – amino acyl site and ‘P’ – peptidyl
site.
• A site allows only the next amino acyl tRNA where P
site is only for initiating tRNA.

5. Difference between prokaryotic and Eukaryotic Ribosomes

6. Composition of prokaryotic & eukaryotic ribosome
• Prokaryotes have 70S ribosomes, each consisting of a small (30S) and a large
(50S) subunit.
• Eukaryotes have 80S ribosomes, each consisting of a small (40S) and large
(60S) subunit.

7. Structure of tRNA

8. Functions:
• rRNA: They form the structural backbone of
ribosome. They play key role in the binding of
mRNA to ribosome and its translation.
• tRNA : It has act as adaptor and it transfers
specific amino acids during protein synthesis.