Genetics: Analysis and Principles 5th Edition by Robert Brooker

Exercise 51

Although 61 codons specify the 20 amino acids, most species display a codon bias. This means that certain codons are used much more frequently than other codons. For example, UUA, UUG, CUU, CUC, CUA, and CUG all specify leucine. In yeast, however, the UUG codon is used to specify leucine approximately 80% of the time
a. The experiment of Figure 13.7 shows the use of an in vitro or cell-free translation system. In this experiment, the RNA, which was used for translation, was chemically synthesized. Instead of using a chemically synthesized RNA, researchers can isolate mRNA from living cells and then add the mRNA to the cell-free translation system. If a researcher isolated mRNA from kangaroo cells and then added it to a cell-free translation system that came from yeast cells, how might the phenomenon of codon bias affect the production of proteins
B. Discuss potential advantages and disadvantages of codon bias for translation.FIGURE 13.7 Elucidation of the genetic code.
Starting material: A cell-free translation system that can synthesize polypeptides if mRNA and amino acids are added. The translation system contained ribosomes, tRNAs, and other factors required for translation. These other factors included enzymes that attach amino acids to tRNA molecules.