Chapter 23

Regulation can occur at many steps in the pathway of gene expression. Give at least one example of a regulator at the level of (a) transcription initiation, (b) protein stability, and (c) protein posttranslational modification.

What are trans-acting factors and cis-acting sites?

The activity of regulatory proteins can be modulated in many different ways. Give at least one example of regulation by each mechanism. a. Protein is blocked by an inhibitor. b. Protein requires a binding partner. c. Active protein is unmodified. d. Active protein is a ligand-bound form. e. Active protein is a form not bound to ligand.

What are positive regulation and negative regulation? Give at least two examples of each for both prokaryotes and eukaryotes.

List at least six different ways in which eukaryotes and prokaryotes differ, with emphasis on issues bearing on transcription and gene regulation.

Compare and contrast the action of transcriptional activators in eukaryotes and prokaryotes.

Compare and contrast the action of transcriptional repressors in eukaryotes and prokaryotes.

What are the two primary roles for activators in eukaryotes? Give several different examples of each.

What is an epigenetic state?

What is cooperative DNA binding? Why might it be useful in stabilizing epigenetic states?

Regulatory systems that control anabolic or catabolic pathways operate in ways that conserve energy for the cell. Give an example of each type of pathway, and indicate how the regulation serves this purpose.

What are eukaryotic pioneer factors, and why is their action important? How are they able to operate? Give an example.

What are iPS cells? How are they produced?