Becker's World of the Cell 9th Edition by Lewis Kleinsmith, Jeff Hardin, Gregory Paul Bertoni

Exercise 4

Attenuation in 25 Words or Less. Complete each of the following statements about attenuation of the trp operon of E. coli in 25 words or less.
(a)The leader sequence can be considered to be a conditional terminator because...
(b)When the gene product of the operon is not needed, the 5' end of the mRNA forms a secondary structure that...
(c)Implicit in our understanding of the mechanism of attenuation is the assumption that ribosomes follow RNA polymerase very closely. This "tailgating" is essential to the model because...
(d)Measurements of rates of synthesis indicate that translation normally proceeds faster than transcription. This supports the proposed mechanism for attenuation because...
(e)If the operon encoding the enzymes in the biosynthetic pathway for amino acid X is subject to this type of attenuation, the leader sequence probably encodes a polypeptide that...
(f)Attenuation makes sense as a mechanism for regulating operons that code for enzymes involved in amino acid biosynthesis because...
(g)Attenuation of this type is not a likely mechanism for regulating gene expression in eukaryotes because...