Gene Regulation and Transcription

These flashcards cover key concepts related to gene regulation, transcription, and translation as discussed in the lecture.

What is a promoter in genetics?

A region of DNA that initiates transcription of a particular gene.

What does RBS stand for?

Ribosome Binding Site.

What is the function of a structural gene?

It is a gene that codes for a protein.

What is the role of RNA polymerase?

It synthesizes RNA from a DNA template.

What occurs during transcription?

The process of copying a segment of DNA into RNA.

What is feedback inhibition?

A regulatory mechanism whereby the end product of a pathway inhibits an earlier step.

What is the difference between activation and repression in gene regulation?

Activation enhances gene expression, while repression decreases it.

What are the three major phases of bacterial growth?

Exponential phase, stationary phase, and death phase.

What is the 5'-UTR in mRNA?

The 5' untranslated region that is upstream of the start codon.

What is an allosteric site?

A site on an enzyme where regulatory molecules can bind, affecting the enzyme's function.

What is the purpose of riboswitches?

Regulatory elements in mRNA that bind small metabolites to control gene expression.

What does the term ‘attenuation’ refer to in transcription regulation?

A regulatory mechanism that prematurely terminates transcription in response to certain metabolite levels.

What is the role of sigma factors in transcription?

They are proteins that bind to RNA polymerase and direct it to specific promoters.

How do transcription factors work?

They bind to specific DNA sequences to regulate the transcription of genes.

What is an operon?

A cluster of genes under the control of a single promoter, transcribed together.

What is the inducer in regulation?

A molecule that initiates gene expression by disabling a repressor.

What is the function of the repressor protein?

It binds to the operator region to inhibit transcription.

What is the difference between mRNA stability and mRNA degradation?

Stability refers to the lifespan of mRNA in the cell; degradation refers to the breakdown of mRNA.

What does the trp operon regulate?

The synthesis of tryptophan in bacteria.

What is the primary function of the ribosome?

To synthesize proteins by translating mRNA.

What is quorum sensing?

A process that bacteria use to monitor their population density through signal molecules.

What is the role of sensor kinases in two-component systems?

They detect environmental signals and initiate a response by autophosphorylation.

What defines a transcription factor?

A protein that regulates gene expression by binding to DNA.

What is the significance of mRNA's 3'-UTR?

It plays a key role in regulating mRNA stability and translation.

What is the consequence of catabolite repression?

It inhibits the expression of certain genes in the presence of preferred nutrients.

How does an allosteric effector function?

By binding at a site other than the active site to alter enzyme activity.

What is the ribosome binding site significance in mRNA?

It is crucial for the initiation of translation.

What does 'constitutive expression' mean in gene regulation?

Gene expression that occurs continuously and does not require regulatory mechanisms.

What are the primary effects of stringent response?

Downregulation of rRNA and tRNA synthesis during amino acid starvation.

What are isoenzymes?

Different enzymes that catalyze the same reaction but are regulated differently.

What role do small regulatory RNAs (sRNAs) play?

They can inhibit or stimulate translation of target mRNAs.

What is the significance of the start and stop codons in translation?

They signal the beginning and end of a protein-coding sequence.