Tell us about the importance of ribosomes in the process of protein biosynthesis in a cell.
Ribosomes, like molecular-sized machines, stamp various proteins at tremendous speed — one medium-sized protein molecule per minute. The best studied ribosomes of one of the bacteria – E. coli. Its ribosomes are obtained in pure form by ultracentrifugation of finely divided bacterial cells. First, large particles settle, which are removed. Then, at very high rotational speeds, ribosomes precipitate. Their subsidence rate is 70 S (S is the Swedberg unit characterizing the subsidence rate).
The ribosome consists of large and small subunits containing various types of rRNA and proteins. The small subunit (CE) binds to mRNA and activated tRNA. Peptidyl transferase in large CE catalyzes the formation of peptide bonds and the addition of amino acids to the growing polypeptide chain. The function of ribosomes is translation (reading the mRNA code and assembly of polypeptides). Ribosomes are divided into mitochondrial and larger cytoplasmic.
