Which of the following conditions leads to maximal expression of the lac operon?
lactose present, glucose absent
lactose present, glucose present
lactose absent, glucose absent
lactose absent, glucose present

Lactose present, glucose absent.

Explanation:

Lac operon may be defined as a cluster of genes that regulate the metabolism of lactose in bacteria. The bacteria always prefer glucose if both glucose and lactose is present in the medium.

The conditions that causes the maximal expression of lactose is the presence of lactose and absence of glucose. This is due to the action of catabolite activator protein and cyclicAMP.

Thus, the correct answer is option (1).

hydroxyl -oh

alcohols, always polar, can form hydrogen bonds with h2o molecules

carboxyl -cooh  

cargoxylic acids, has acidic properties which is a source of hydrogen ions, found in cells in ionized for with a charge of oh-1

carbonyl > co

ketone if within skeleton, aldehyde if group is at the end of skeleton, k & a may be structural isomers, it determines 2 sugars (ketose & aldose)

amino -nh2

amines, acts as a base, it can pick up h+ ions from surrounding solution, ionized with charge of 1+

methyl ch2

addition to rna/dna affects and gene expression

phosphate -opo3 ²⁻

organic phosphates, contributes to negative charge to, molecule that it is a part of, and potential to react with h20

sulfhydryl -sh

thiols, cross-linking stabilize the protein, and it is structure

but there is no

i guess you forgot putting it.