Question

The lac operon genes only become expressed if​

Answer 1

Explanation:

It's expressed only when lactose is present and glucose is absent. Two regulators turn the operon "on" and "off" in response to lactose and glucose levels:

Answer 2

The lac operon genes only become expressed in Metabolism

Explanation:

• Genes important in metabolism are found in the Lac operon.
• Lactose binds to the repressor, and therefore the lac operon genes become active. Lactose binds to the repressor's operator, OD.
• Lac repressor binds to DNA in a non-specific manner (initial scene generated from 1osl, 20 NMR models), allowing it to travel quickly along the double helix until it reaches the lac operator sequence ("facilitated diffusion").
• A helix-turn motif is used in the DNA binding domain (Alpha Helices, Turns).
• The hinge regions are disordered during non-specific binding (indicated by the range of positions of the 20 models).
• In the model, the DNA double helix appears to be straight, but its straightness is likely to vary depending on sequence.