in our splicing case). Gene activity is regulated by the specific interactions of the trans-acting products(usually proteins)with the cis-acting sequences(usually sites in DNA/RNA). In more formal terms A gene is a sequence of dNa that codes for a diffusible product. This product may be protein(as in the case of the majority of genes)or may be rna(as in the case of genes that code for tRNA and rRNA). The crucial feature is that the product diffuses away from its site of synthesis to act elsewhere. Any gene product that is free to diffuse away from the gene that made it to function elsewhere is described as trans-acting The description cis-acting applies to any sequence of dNA/RNA functions exclusively as a DNA/RNA sequence in situ, affecting only the dna/rna to which it is physically linked -----GENE VIII 8. What are the challenges of translation of the genetic information residing in mRNA into a protein 4 points)? What are the four components of translation machinery 4 points)? Please describe the oles of each component in translation (remember the relationship between the structure and function)(12 points). Translation faces two main challenges(4 points) The genetic information in mRNA cannot be recognized by amino acids Therefore, the genetic code has to be recognized by an adaptor molecule( translator), and this adaptor has to accurately recruit the corresponding amino acid Four components of translation machinery and their roles in translation(8 points) 1)Messenger RNA(mRNA) serves as the template in translation(1) The coding region in the mRNA consists of a series of three-nucleotide long units called codons(1). The prokaryotic mRNA and eukaryotic mRNA employ different strategies to recruit the ribosome--the rBs in prokaryotes and the 5 cap in 2)tRNA transfer RNA is the molecular adaptor between the codon and the corresponding amino-acid (I point). The tertiary structure of the tRNA resembles an inverted L, in which the acceptor stem and the anticodon loop are positioned at the two extreme ends. The amino acids is attached to the acceptor stem, and the anticodon loop base pair with the three letter code in mRNA(2) 3) Aminoacyl-tRNA synthetase(1 ). The enzyme catalyzes the addition of amino acid to its cognate tRNA, which process is termed"charging". The enzyme catalyzes the charging in two separate steps, first attaching AMp to the-COOH group of the amino acid and then the appropriate trna displacing the amp to covalently link with the amino acid (2) 4) Ribosome (1). A two-subunit complex which comprises of both proteins and TRNAS. The large subunit contains the peptidyl-transferation center, catalyzing the peptide bond formation and the small subunit which contains the decoding center is where the codon-anticodon reaction takes place. (2) 9. Leucine has six codons. UUA, UUG CUU CUC CUA and CUG please predict atin our splicing case). Gene activity is regulated by the specific interactions of the trans-acting products (usually proteins) with the cis-acting sequences (usually sites in DNA/RNA). In more formal terms: A gene is a sequence of DNA that codes for a diffusible product. This product may be protein (as in the case of the majority of genes) or may be RNA (as in the case of genes that code for tRNA and rRNA). The crucial feature is that the product diffuses away from its site of synthesis to act elsewhere. Any gene product that is free to diffuse away from the gene that made it to function elsewhere is described as trans-acting. The description cis-acting applies to any sequence of DNA/RNA functions exclusively as a DNA/RNA sequence in situ, affecting only the DNA/RNA to which it is physically linked. -----GENE VIII] 8. What are the challenges of translation of the genetic information residing in mRNA into a protein (4 points)? What are the four components of translation machinery (4 points)? Please describe the roles of each component in translation (remember the relationship between the structure and function) (12 points). Translation faces two main challenges (4 points): The genetic information in mRNA cannot be recognized by amino acids. Therefore, the genetic code has to be recognized by an adaptor molecule (translator), and this adaptor has to accurately recruit the corresponding amino acid. Four components of translation machinery and their roles in translation (8 points): 1) Messenger RNA (mRNA) serves as the template in translation (1’) The coding region in the mRNA consists of a series of three-nucleotide long units called codons (1’). The prokaryotic mRNA and eukaryotic mRNA employ different strategies to recruit the ribosome--the RBS in prokaryotes and the 5' cap in eukaryotes (1’). 2) tRNA transfer RNA is the molecular adaptor between the codon and the corresponding amino-acid (1 point). The tertiary structure of the tRNA resembles an inverted L, in which the acceptor stem and the anticodon loop are positioned at the two extreme ends. The amino acids is attached to the acceptor stem, and the anticodon loop base pair with the three letter code in mRNA (2’) 3) Aminoacyl-tRNA synthetase (1’). The enzyme catalyzes the addition of amino acid to its cognate tRNA, which process is termed “charging”. The enzyme catalyzes the charging in two separate steps, first attaching AMP to the-COOH group of the amino acid and then the appropriate tRNA displacing the AMP to covalently link with the amino acid (2’). 4) Ribosome (1’). A two-subunit complex which comprises of both proteins and rRNAs. The large subunit contains the peptidyl-transferation center, catalyzing the peptide bond formation and the small subunit which contains the decoding center is where the codon-anticodon reaction takes place. (2’) 9. Leucine has six codons, UUA, UUG CUU CUC CUA and CUG please predict at