General
A type of regulation that the binding of an activator stimulates transcription
What is positive regulation?
Consists of promoter, operator, and structural genes
What does an operon consist of?
proteins that bind to DNA sequences to regulate gene transcription (a part of promoter region)
What are transcription factors?
the process by which a cell makes an RNA copy of a piece of DNA
What is transcription
Genes expressed all the time
What are constitutive genes?
Name of specific inducible operon in prokaryotes
What is the Lac operon?
process of splicing pre-mRNA (intron parts) that produces different sequences of proteins.
What is alternative splicing?
transcriptional regulators that bind directly or indirectly to transcription factors (work in conjunction with repressors)
What is a corepressor?
Regulation where a repressor binds near the promoter to prevent transcription.
What is negative regulation?
Name of specific repressible operon in prokaryotes
What is the trp operon?
a type of regulation that happens after translation that degrades/destroy RNA by binding with mRNA
What is microRNA?
changes in gene expression that do not involve changes in DNA sequences
What is epigenetics?
genes expressed only when their proteins are needed by the cell.
What are inducible genes?
Describe what happens when lactose is absent and present in a prokaryote
Lactose absent: operon turned off, no transcription
Lactose present: operon turned on, transcription starts
part of gene (box) that transcription factors bind to that defines the direction of translation
What is the TATA box?
protein needed for initiation of transcription that direct RNA polymerase to specific promoters
What are sigma factors?
region of DNA where transcription of a gene is initiated since they control the binding of RNA polymerase to DNA
Describe what happens when tryptophan is absent and present in a prokaryote
Tryptophan absent: operon turned on, transcription proceeds
Tryptophan present: operon turned off, corepressor binds to repressor, transcription is blocked
These two measures prevent the produced RNA from degrading (hint: one goes on the 3' tail and other goes on 5')
What is the 3' poly A tail and 5' cap?
the modification of histone proteins in nucleosomes also affects transcription
What is chromatin remodeling?