Concepts and formula to Remember

Protein Synthesis:

• Aminoacyl-tRNA synthetases enzymes charge tRNA molecules with amino acids for translation.
• Codons are three-nucleotide sequences in mRNA that code for amino acids.
• The initiation codon (AUG) marks the start of protein synthesis.
• Stop codons (UAA, UAG, UGA) signal the end of translation.
• Ribosomes facilitate tRNA-mRNA pairing and protein synthesis.

Initiation of Protein Synthesis:

• Bacterial ribosomes consist of small (30S) and large (50S) subunits.
• Eukaryotic ribosomes are larger, with small (40S) and large (60S) subunits.
• Initiation factors help assemble ribosomal subunits.
• Steps in prokaryotic initiation: mRNA binding, initiator tRNA binding (AUG).
• Steps in eukaryotic initiation: mRNA binding, small ribosomal subunit assembly.

Elongation of Protein Chain:

• Elongation has three phases: codon recognition, peptide bond formation, translocation.
• Charged tRNA enters the A site guided by mRNA codon.

Termination of Protein Synthesis:

• Termination occurs at stop codons.
• Release factors recognize stop codons, leading to protein release.

Deconstruction of Ribosomal Complex:

• After termination, the ribosomal complex disassembles, releasing mRNA and tRNA.