Translation requires 3 steps

Initiation

-factors (protein) assemble ribosomal units (rRNA), mRNA initiation tRNA -starts at codon, AUG, which codes for methionine -ribosome has 3 stops for tRNA (binding sites) 1. A: Amino site 2. P: Peptide site 3. E: Exit site

Termination

-release factor -polypeptide & ribosomal separate (release) -polypeptide is further processed by cell into protein

Translation Overview

-second step of protein synthesis -codons of mRNA airs w/ anticodon of tRNA at the ribosome (rRNA) -tRNA drops appropriate amino acid -bonds are made between a.a.'s (peptide bond) to make a polypeptide -3 steps: initiation, elongation, termination -first 2 steps require energy

Elongation

-the peptide chain increases in length one a.a. at a time -requires an elongation factor

Steps of elongation (4)

1. tRNA is at "P" site and another carries next a.a. to "a" site 2. Next tRNA is in place at "a" site and peptide chain is moved to this tRNA 3. Nrg & ribosomal unit is required for transfer & peptide bond forms bt a.a. 4. Translocation occurs: mRNA move forward one codon length , peptide bearing tRNA at "p" site, "spent" tRNA exists.