Chapter 12

tRNAs

RNA molecules that bind specific amino acids and recognize mRNA sequences, interacting with ribosomes and aminoacyl-tRNA synthetases.

Ribosome

Cellular structure where translation occurs, made of proteins and RNA, requiring additional factors for initiation, elongation, and termination.

Genetic Code

Triplet codons specify amino acids, non-overlapping and comma-less, with degeneracy, uniformity, and universality, where ribosomes move along mRNA three bases at a time.

Codon-Anticodon Recognition

tRNA molecules bind to mRNA via complementary base pairing, with a Wobble position allowing for variations in codon recognition.

Amino Acid Activation

Process catalyzed by aminoacyl-tRNA synthetase, involving specific binding of amino acids to tRNA through ester formation.

Ribosome Structure

Cellular machine for protein synthesis, composed of proteins and RNA, with A, P, and E binding sites for tRNAs during translation.

Prokaryotic Translation

Initiation involves fMet-tRNA binding to the ribosome, elongation uses APE sites on the ribosome, and termination occurs at stop codons with release factors.

Chain Initiation

Process starting with fMet-tRNA binding to the ribosome, involving initiation factors, GTP, and mRNA binding to form the initiation complex.

Chain Elongation

Process where aminoacyl-tRNAs bind to the ribosome, peptide bonds are formed, and ribosome translocates along mRNA with the help of elongation factors.

Termination

Process where stop codons are recognized by release factors, leading to the release of the synthesized protein and disassembly of the ribosome.

Protein Synthesis Energy

Energy requirements for translation, including ATP for amino acid activation, GTP for translocation, and additional GTPs for elongation and termination.

Protein Synthesis Inhibitors

Compounds like tetracycline, chloramphenicol, and streptomycin that interfere with translation by binding to the ribosome or affecting the genetic code reading.

Post-translational Modification

Processes like N- and C-terminus modifications, disulfide bond formation, and attachment of groups like carbohydrates or ubiquitin to proteins after translation.