2023 Preflashcard on Operons

Front

What is the function of the lac operon in bacteria?

Back

The lac operon allows bacteria to metabolize lactose when it is present in the environment.

Front

What triggers the expression of genes in the lac operon?

Back

The presence of lactose in the cell.

Front

True or False: Both eukaryotes and prokaryotes have operons.

Back

False. Only prokaryotes have operons.

Front

What role does the repressor protein play in gene expression?

Back

The repressor protein prevents RNA polymerase from binding to the promoter and reading the gene.

Front

What is the promoter in the context of gene expression?

Back

The promoter is the binding site for RNA polymerase in eukaryotes.

Front

What is a repressible operon?

Back

A repressible operon is one that is usually active but can be turned off in the presence of a specific molecule.

Front

What is the difference between an inducible operon and a repressible operon?

Back

An inducible operon is usually off and can be turned on by an inducer, while a repressible operon is usually on and can be turned off by a repressor.

Front

What is the role of RNA polymerase in gene expression?

Back

RNA polymerase synthesizes RNA from the DNA template, allowing for gene expression.

Front

What happens to the lac operon when glucose is present?

Back

When glucose is present, the lac operon is repressed, as bacteria prefer to use glucose over lactose.

Front

What is an operator in the context of an operon?

Back

The operator is a segment of DNA that a repressor protein binds to, blocking RNA polymerase from transcribing the genes.