Modulating Transcription Flashcards
1
Q
What is required for prokaryotic growth?
A
- nutrient rich environment containing amino acids and carbohydrates
- favourable temperatures
2
Q
Housekeeping Genes
A
- required all of the time for normal function
- include genes that are important for structural proteins of the cell, RNA/DNA polymerase and genes that code for ribosomal proteins
3
Q
Regulated Genes
A
can be turned off/on on an as-needed basis
4
Q
When _________ is absent, the cell can metabolize _________
A
glucose
lactose
5
Q
lactose is metabolized into glucose and galactose by
A
B-galactosidase
6
Q
How is B-galactosidase made?
A
by turning on transcription of the B-galactosidase gene (occurs when lactose is available)
7
Q
Mohod & Jacob
A
-observed that lactose had to be present in order for B-galactosidase to be produced
8
Q
Gene Expression
A
-functional product of the gene is made, modified and activated
9
Q
Transcriptional Control
A
- DNA to mRNA
- controls the amount to mRNA produced in the cell
- cell can activate or inhibit transcription by controlling the binding of proteins to a promoter
- has to transcribe, translate and modify the enzyme which takes longer
- doesn’t waster energy making polypeptide or mRNA unless needed
10
Q
Translational Control
A
- mRNA to Protein
- rate at which translation occurs affects amount of protein produced
- amount of protein produced depends on stability of mRNA
11
Q
Post-translational Control
A
- Protein to Activated Protein
- allow polypeptide to be folded into functional 3D structure
- more than a dozen post-translational modifications regulate the ability of the protein to become active or inactive by driving the assembly into complexes, the binding of substrates or the unmasking of enzymatic domains
- allows the cell to stockpile inactive proteins and turn them on when a signal is received
