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What type of regulation does the trp operon exhibit?

The trp operon is regulated by the trp repressor. When bound to tryptophan, the trp repressor blocks expression of the operon. Tryptophan biosynthesis is also regulated by attenuation (a mechanism based on coupling of transcription and translation).

Which of the following are features of operons?

Another common feature of operons is that their genes are clustered on the bacterial chromosome. This chromosome is a large circular molecule of DNA. The genes of an operon are arranged in a consecutive and linear fashion at a specific location on the bacterial chromosome.

What are the three components of an operon?

An operon is made up of 3 basic DNA components:

  • Promoter – a nucleotide sequence that enables a gene to be transcribed.
  • Operator – a segment of DNA to which a repressor binds.
  • Structural genes – the genes that are co-regulated by the operon.

What is the lac operon model?

The lac operon is an operon, or group of genes with a single promoter (transcribed as a single mRNA). The genes in the operon encode proteins that allow the bacteria to use lactose as an energy source.

What are the four components of an operon?

An operon is a unit of the bacterial chromosome consisting of the following components:

  • A regulatory gene. The regulatory gene codes for a regulatory protein.
  • An operator. The operator is the region of DNA of the operon that is the binding site for the regulatory protein.
  • A promoter.
  • Structural genes.

Is the lac operon positive or negative control?

The lac operon exhibits both systems. It is a negative control system because expression is typically blocked by an active repressor (the lac repressor) that turns off transcription.

What does Lac Y do?

The LacY gene codes for the proteinBeta-galactoside permease. It is a transmembrane symporter found in the cytoplasmic membrane that regulates the transport of lactose into the cell. It does this by pumping Beta-galactosides, including lactose, into the cell in the same direction as the proton gradient.

What happens if the operator is mutated?

What happens if there is a mutation observed in the operator gene in the lac operon? if the repressor binds more strongly, there would be less transcription. if the repressor has difficulty binding then it is possible that the operon would be turned on when not needed.

What happens to lac operon when glucose is present?

If both glucose and lactose are both present, lactose binds to the repressor and prevents it from binding to the operator region. The block of lac gene transcription is thus lifted, and a small amount of mRNA is produced. Lactose still prevents the repressor from binding to the operator region.

Who discovered lac operon?

Francois Jacob

What does Iptg stand for?

Isopropyl β- d-1-thiogalactopyranoside