Читать книгу Snyder and Champness Molecular Genetics of Bacteria - Tina M. Henkin - Страница 246

1 Which do you think came first in the very earliest life on Earth, DNA, RNA, or protein? Why?

2 Why is the genetic code universal?

3 Why do you suppose prokaryotes have polycistronic mRNAs but eukaryotes do not?

4 Why do you suppose mitochondrial genes show differences in their genetic code from chromosomal genes in eukaryotes?

5 Why is selenocysteine inserted into proteins of almost all organisms but into only a few sites in a few proteins in these organisms?

6 Why do so many antibiotics inhibit the translation process as opposed to, say, amino acid biosynthesis?

7 Why do you think chaperonins have two linked chambers and alternate the folding of proteins between the two chambers?

8 List all the reasons you can think of why bacteria would regulate the expression of their genes.

9 Why do bacteria have so many different mechanisms for localization of proteins to different sites?