BIO 325 - Molecular Biology of the Cell: Control of Gene Expression

These flashcards cover key concepts from the lecture on the control of gene expression in molecular biology, focusing on transcriptional regulation, operons, RNA interference, and gene control mechanisms.

What is the main function of transcriptional regulators in gene expression?

They control gene expression by either aiding or preventing RNA polymerase binding to promoter sequences.

What is the trp operon responsible for?

The trp operon controls tryptophan biosynthesis.

What type of control does the lac operon exhibit?

The lac operon exhibits inducible negative control.

What happens when lactose is available in relation to the lac operon?

Lactose prevents the repressor from binding to the operator, allowing transcription to occur.

What is RNA interference (RNAi)?

RNA interference is the process by which double-stranded RNA (dsRNA) silences gene expression by degrading mRNA.

What role does the CAP protein play in the lac operon?

CAP is a transcription activator that binds to DNA and is necessary for RNA polymerase binding, induced by cyclic AMP (cAMP).

What are examples of cis-regulatory elements?

Cis-regulatory elements include promoters, promoter-proximal sites, and enhancers.

What does combinatorial control in eukaryotic gene expression involve?

It involves the action of multiple transcription factors and regulatory sequences that together control gene expression.

What effect does the presence of cortisol have on gene expression?

Cortisol activates the cortisol receptor, coordinating the expression of several genes.

What is the significance of microRNAs in gene expression?

MicroRNAs regulate gene expression at the translation level, providing another layer of control.