Chapter 9, Problem 12P

Summary Introduction

To analyze:

The following diagram of a eukaryotic ribosome contains several errors.

1. Examine the diagram carefully, and each error is to be identified.

2. Redraw the diagram, and using the $\text{mRNA}$ sequence each error is to be corrected.

Introduction:

Ribosome is one of the essential organelles in the cell that carries out protein synthesis. Since bacteria do not have membrane bound organelles, the ribosomes float in the cytoplasm. Ribosome it is complex of protein and rRNA, and it is made up of $\text{2}$ subunits- large and small. It decodes the genetic message into proteins.

Translation is the process of production of proteins by mRNA decoding. The crucial step in protein synthesis is peptidyl transfer, i.e., newly synthesized amino acids are attached with peptide bonds that are transferred from one tRNA molecule to the next. These amino acids have specific codons, and all these amino acids synthesize polypeptide chain.

Prokaryotes have $\text{70S}$ ribosome- $\text{50S}$ & $\text{30S}$ are subunits of it. Eukaryotes have $\text{80S}$ ribosome- smaller $\text{40S}$ subunit and larger $\text{60S}$. There are complete $\text{4}$ binding sites on Ribosome – one for mRNA and three for tRNA. Ribosomal larger subunit has $\text{3}$ sites for amino acid synthesis – E, P, A.