Chapter 15 Regulation Of Gene Expression Flashcards
Prokaryotes and Eukaryotes alter gene expression in response
To their changing environment
A cell can regulate the production of enzymes by
Feedback inhibition or gene regulation
Gene expression in bacteria is controlled by a process called
The Operon model
A group of functionally related genes can be coordinately controlled by a single
On-off switch
The regulatory switch is a segment of dna called
An operator
An ________is the entire stretch of DNA that includes the operator, the promotor, and the genes they control
Operon
The Operon can be switched off by a protein
Repressor
The repressor is the product of a separate
Regulatory gene
A _________ is a molecule that cooperates with a repressor protein to switch an Operon off
Corepressor
Two types of negative gene regulation
Repressible
Inducable
A repressible Operon is usually
On
An inducible Operon is usually
Off
A molecule called the__________ inactivates the repressor
Inducer
Inducible enzymes usually function in
Catabolic pathways
Repressible enzymes usually function in
Anabolic pathways
Differential gene expression
The expression of different genes by cells within the same genome
Gene expression is commonly controlled at
Transcription
Histone Acetylation
Acetyl groups are attached to positively charged lysine and histone tails
DNA methylation
Is the addition of methyl groups to certain bases in DNA, usually cytosine
Epigenetic Inheritance
The inheritance of traits transmitted by mechanisms not directly involving the nucleotide sequence
Control Elements
Segments of non coding DNA that serve as binding sites for transcription factors
Enhancers
Distal control elements may be far from a gene or located in an intron
Alternative RNA splicing
Different mRNA molecules are produced from the same primary transcript
Eukaryotic mRNA generally survives longer than
Prokaryotic mRNA
