Can you match terms related to operons to their definitions?
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inducer
operator
genes of an operon
??(??) ?is a stretch of DNA consisting of an operator, a promoter, and genes for a related set of proteins, usually making up an entire metabolic pathway.
The is/are arranged sequentially after the promoter.
??(??) ? ?is a specific nucleotide sequence in DNA that binds RNA polymerase, positioning
regulatory gene it to start transcribing RNA at the appropriate place.
promoter
repressor
??(??) ? ?codes for a protein, such as a repressor, that controls the transcription of another gene or group of genes.
Regulatory proteins bind to the to control expression of the operon.
The correct answer and explanation is:
Here are the correct matches for the terms related to operons:
- Operon is a stretch of DNA consisting of an operator, a promoter, and genes for a related set of proteins, usually making up an entire metabolic pathway.
- Genes of an operon are arranged sequentially after the promoter.
- Promoter is a specific nucleotide sequence in DNA that binds RNA polymerase, positioning it to start transcribing RNA at the appropriate place.
- Regulatory gene codes for a protein, such as a repressor, that controls the transcription of another gene or group of genes.
- Operator is the DNA sequence where regulatory proteins bind to control expression of the operon.
Explanation:
Operons are essential gene regulation systems in prokaryotes, mainly bacteria. They allow cells to efficiently control gene expression, ensuring that proteins are only produced when needed. The operon consists of a promoter, operator, and structural genes.
- Promoter: This is a specific DNA sequence that serves as a binding site for RNA polymerase, the enzyme responsible for transcribing DNA into mRNA. Without a promoter, transcription cannot begin.
- Operator: This is a regulatory sequence located between the promoter and the structural genes. It acts as a switch, controlling the access of RNA polymerase to the genes. Regulatory proteins, such as repressors, bind here to block transcription.
- Genes of an operon: These are the functional genes arranged in sequence after the promoter. They encode proteins involved in the same metabolic pathway, such as enzymes needed to break down lactose in the lac operon.
- Regulatory gene: This gene is located outside the operon and produces regulatory proteins like repressors or activators. These proteins determine whether the operon is on or off by interacting with the operator.
- Inducers and repressors: Some operons (like the lac operon) require an inducer (e.g., lactose) to inactivate the repressor, allowing transcription. Others, like the trp operon, use a repressor to prevent unnecessary protein production.
Operons provide bacteria with a cost-effective way to regulate genes, ensuring that energy is not wasted on producing unnecessary proteins.
Image Generation:
I’ll now generate an image illustrating the structure of an operon, including the promoter, operator, genes, regulatory gene, and their interactions.
Here’s the educational diagram illustrating the structure and function of a bacterial operon. It highlights the promoter, operator, regulatory gene, structural genes, RNA polymerase, repressor protein, and inducer molecule, showing how gene expression is regulated. Let me know if you need any modifications or explanations!
