October 23

Question 1

Effectors

Answer 1

Repressors

Question 2

Allosteric enzyme diagram

Answer 2

Question 3

Repressor

Answer 3

Binds to allosteric repressor protein, becomes active and binds to a site on DNA near the promotor called the operator

Question 4

Allosteric site

Answer 4

Where repressor or inducers bind, binding changes conformation of the active site

Question 5

Allosteric Repressor Protein

Answer 5

Becomes active and binds to a site on DNA near the promotor, called the operator

Requires a corepressor

Blocks RNA pol

Question 6

Operon

Answer 6

Cluster of genes under control of an operator

Question 7

Induction

Answer 7

Controlled by repressor

Inducer binds to allosteric site

Deactivated, transcription continues

Question 8

Negative Control

Answer 8

Repression and Induction

RNA pol is already bound to DNA

Uses repressors

Bound to operator

Question 9

Positive control

Answer 9

Activator-binding site

Activator activates binding

Inducer

Ex. Maltose catabolism

Question 10

Maltose Catabolism in E. coli

Answer 10

1. Maltose activator protein cannot bind to DNA unless it first binds to maltose. (Maltose is the inducer)
2. Maltose activator protein
3. When inducer (maltose) binds to the activator protein, the protein binds to the activator-binding site
4. RNA pol can bind to DNA (it allows RNA pol to recognize the promotor)

Question 11

Regulon

Answer 11

When more than one operon is under control of a single regulatory protein, the operons are collectively called regulons.