Explain how the lac operon is regulated, including all negative and positive components of regulation.

Explanation:

Three enzymes for lactose metabolism are grouped in the lac operon: lacZ (β-galactosidase), lacY (permease) and lacA (trans-acetylase). The transcription of this operon occurs only when lactose is available to digest, presumably to avoid wasting energy.  Apart from these protein-coding genes we have P(promoter), O(operator and CBS(Cap-binding site), sequences that work as binding sites for transcriptional regulation.

Negative components: An important regulator is lacI when four of these molecules assemble they form a repressor, this will bind to the promoter, this won't allow the operon to be transcribed as long as the operator is occupied by a repressor. LacI can also prevent lactose to bind to the operator by binding with it and changing its shape.

Positive components: cAMP binding protein is another molecule that when is bound to CBS improves the chance of RNA polymerase to bind to the promoter to initiate transcription.

I hope you find this information useful! Good luck!

I adden an image that ilustrates what I explained.

i think it is dna, i'm not totally sure but i think it might be.

the answer is z.

the human body has five levels of organization. level 1: cells. cells are the basic units of life and form the first level of organization. cells in the human body have specific functions. examples include nerve cells, blood cells, liver cells, and so on.