26. Nucleic Acids and Protein Synthesis

Tuftsin is an immunostimulator tetrapeptide having the following sequence:

                                   Thr–Lys–Pro–Arg

Write a possible sequence for the gene (Informational & template strand) that codes for this tetrapeptide.

What amino acid sequence is coded for by the mRNA base sequence CUC-AUU-CCA-UGC-GAC-GUA?

Gln-His-Pro-Gly is the sequence of a molecule known as progenitor thyrotropin-releasing hormone (pro-TRH). If we were searching for pro-TRH genes, we would need to know what sequence of bases in DNA we should be looking for. Use the following boxes to indicate answers to parts (a)–(d).

a. What RNA sequence could code for these four amino acids?

What is an anticodon, and on what kind of nucleic acid is it found?

What tetrapeptide is synthesized from the informational DNA sequence G-T-C-A-G-T-A-C-G-T-T-A?

The codons UGA, UAA, and UAG do not code for amino acids. What is their role as codons in mRNA?

What are the three steps of translation?

The following sequence is a portion of the DNA template strand: TGT GGG GTT ATT

b. What are the anticodons of the tRNAs?