Biology Forums - Study Force

    When tryptophan levels are low, transcription is initiated and continues through the leader region into the structural genes, resulting in the production of a polycistronic mRNA and, ultimately, the enzymes required for the biosynthesis of tryptophan.
    When tryptophan levels are low, transcription of the leader sequence proceeds, but mRNA synthesis is terminated approximately 140 nucleotides along the transcript.
    The levels of tryptophan in the environment affect only repression of the trp operon and do not affect attenuation.
    When tryptophan is present at high concentrations, the repressor binds to the operator and transcription is initiated and not terminated. As a result, the enzymes required for the biosynthesis of tryptophan are translated.

it is difficult to define "normal" and "abnormal."
personal distress is the one criterion that defines abnormality.
the criteria differ depending on the cause of the psychological disorder.
the criteria differ depending on whether the individual has a psychological disorder or a psychological dysfunction.

When tryptophan levels are low, transcription is initiated and continues through the leader region into the structural genes, resulting in the production of a polycistronic mRNA and, ultimately, the enzymes required for the biosynthesis of tryptophan.