Genetic Regulation in Molecular and Cellular Biology

lacZ

Gene coding for β-galactosidase in E. coli.

ATP cost

1 ATP equivalent per base for protein synthesis.

mRNA

Messenger RNA transcribed from DNA for protein synthesis.

polysome

Complex of multiple ribosomes translating mRNA.

transcription initiation

Primary regulation point for gene expression.

regulated expression

Genes turned on/off based on cellular needs.

constitutive expression

Genes expressed continuously, regardless of conditions.

operon

Multiple genes controlled by a single promoter.

inducible operon

Operon that can be activated when needed.

repressible operon

Operon that is active by default, can be turned off.

β-galactosidase

Enzyme that breaks down lactose in E. coli.

lac operon

Operon regulating lactose metabolism in E. coli.

mRNA stability

Influences protein levels post-transcription.

translation initiation

Regulation point affecting protein synthesis efficiency.

Shine-Dalgarno sequence

Ribosomal binding site in bacterial mRNA.

corepressor

Molecule that inhibits gene expression in repressible operons.

allosteric regulation

Protein activity modulation via conformational changes.

feedback inhibition

End product inhibits an earlier step in pathway.

transcriptional regulation

Energy-efficient gene expression control mechanism.

post-translational regulation

Quick response mechanism for protein activity adjustment.

chromatin remodeling

Modification of chromatin structure to regulate gene access.

activators

Proteins that enhance gene transcription by binding DNA.

repressors

Proteins that inhibit gene transcription by binding DNA.

Mediator

Complex that facilitates interaction between transcription factors and RNA polymerase.

pioneer factors

Transcription factors that initiate chromatin remodeling.

histone modifying enzymes

Enzymes that add chemical groups to histones, altering gene expression.

nucleosome

DNA-histone complex that packages DNA in eukaryotes.

transacetylase

Enzyme involved in lactose metabolism, part of lac operon.

β-galactosidase levels

Can be adjusted based on mRNA stability and translation.

iron regulation

Example of protein level regulation based on iron availability.