Control of gene expression Flashcards
A multicellular organism has different types of cells that form what
Tissues and organs
Do all cells have the same DNA?
Yes
Different cell types produce different ________
Proteins
Differentiation is the process by which the cells take on characteristic physiological and morphological traits that are necessary for what cell state
Terminal cell state
Differentiation is the result of what
Regulation gene expression
General strategies relate to controlling transcription, translation, and the stability of what
Activity of mRNA and proteins in a cell
What is a common way to regulate expression
To limit the amount of transcription that occurs
What is the general strategy used to regulation gene expression
Use DNA-binding proteins to affect how well RNA polymerase binds a promoter
What are operons
groups of genes under the control of a single promoter
One promoter is found where in an operon
the beginning
One large piece of mRNA is transcribed rather then what
and individual RNA molecule
Multiple proteins are produced from where
The large transcript
Operons can be used as what
How protein activation and inactivation regulate gene expression
Proteins that inhibits transcription are called
Repressor proteins
What are activator proteins
regulatory proteins that increase transcription by enhancing RNA polymerase binding at the promoter
what are the main functions of trp operons
-encodes enzymes to produce tryptophan
-Trpr decreases transcription when it is active
the activity of trp depends on what
the amount of tryptophan present in the cell
What does TrpR do
Binds an operator site near the trp promoter
TrpR is allosteric with binding sites for what
DNA and tryptophan
Tryptophan binds TrpR and opens the DNA binding site to activate TrpR which then binds what
the DNA
If there is no tryptophan then what happens to the TrpR
it is inactive
The lac operon has two DNA binding sites for two different what
Regulatory proteins
What are the two regulatory proteins
Lacl - lac repressor
CAP - catabolite activator protein
Both proteins are what
Allosteric
