Central Dogma And Lac Operon Regulation — a labelled NEET Biology diagram with a definitions lexicon.
Central Dogma and Lac Operon Regulation Labelled parts: DNA, RNA, mRNA, Protein, Central dogma, Transcription, Translation, DNA polymerase, RNA polymerase, Ribosome, Amino acids, tRNA, lac operon, lacI, lacO, lacZ, lacY, lacA, Promoter, Operator, Repressor protein, Allolactose, Induced state, Repressed state. The fundamental concept describing the flow of genetic information in biological systems: DNA RNA Protein. Replication (DNA DNA) is also included. FYI: Transcription (DNA RNA) occurs in the nucleus of eukaryotes, while translation (mRNA Protein) occurs on ribosomes in the cytoplasm. A cluster of genes (lacZ, lacY, lacA) in E. coli regulated by a single promoter and operator. It controls the metabolism of lactose when glucose is scarce. FYI: The operon structure allows the cell to efficiently synthesize all necessary enzymes simultaneously when lactose is present. The gene encoding the repressor protein for the lac operon. This protein binds to the lacO operator when lactose is absent, blocking transcription. FYI: The lacI repressor is constitutively expressed, meaning it is always present in the cell. The operator sequence within the lac operon. It is the binding site for the lacI repressor protein, controlling the initiation of transcription. FYI: When allolactose is present, it acts as an inducer, binding to the repressor and causing it to detach from the lacO site. The gene encoding -galactosidase, an enzyme that hydrolyzes lactose into glucose and galactose. It is part of the lac operon. FYI: This enzyme is crucial for the initial breakdown of lactose into usable monosaccharides. The gene encoding lactose permease, a membrane protein that transports lactose from the environment into the cell. It is part of the lac operon. FYI: Without the lacY permease, the cell cannot accumulate enough lactose to metabolize it. The gene encoding transacetylase, an enzyme involved in the detoxification of toxic metabolic byproducts. It is part of the lac operon. FYI: While part of the operon, the function of lacA is often considered less critical for basic lactose metabolism compared to lacZ and lacY. An isomer of lactose that acts as the inducer molecule for the lac operon. It binds to the repressor protein, inactivating it. FYI: The presence of allolactose signals the cell that lactose is available, thus activating the operon.