Gene Structure And Regulation Flashcards
Pathogenicity island is
Block of gene that is the pathogenic mechanism.
There are 3 types of recombination. What are they and what do they do?
1: homologous: needed same
2: site specific: flexible and recognize sites
3: transposition: insertions into DNA
Bacteria genes have what structure? What regions?
Promoter. Gene code. Termination region.
What are the start and stop codon?
Start: ATG.
STOP: taa tag tga
What is the diff between operon, regulon, and Stimulon?
Operon: DNA segment codes for multiple proteins. (1 mRNA)
Regulon: many genes/operons influenced by 1 regulating protein
Stimulon: multiple genes/operons influenced by 1 stimulus.
When does translation stop?
Stop codon
When’s transcription stop?
Hits as transcription terminator.
What are some differences between pro and eukaryotic gene expression?
Introns not in bacteria Pro genes coupled Transcript/Lation paired in pro No modified RNA in pro Pro have n acetylation methionine. (chemo attractant)
Nonsense vs missense?
Nonense is early stop
Missense is diff amino acid, no changed pheno.
What repair system in bacteria is highly error prone?
SOS
Activators and repressors are also called?
Activators are positive regulation
Repressors are neg regulation.
What’s an inducer?
It’s a small molecule that co-stimulates along with the activator.
How does the Lac operon work?
Diff conc of glu and lactose cause expression of lactose enzymes.
How Does lax operon make lots of protein?
Low glucose (high camp - CAP) Lactose inducer (allolactose) binds the inhibitor, freeing it.
Thus high amounts are made.
If no lactose is present, then there will be ____ expression?
No!
If high amounts of lactose and glucose, what happens?
Only the allo lactose inducer binds the repressor and SOME protein is expressed.
Trp operon. Is the repressor on or off when bound to Trp?
Repressor needs Trp to bind DNA. Therefore the expression is always on.
If the ribosomes are quick translators and which number proteins bind hairpin? What this mean?
3-4. Therefore no Trp is made.
When Trp isn’t present, the ribosomes stalls and what number proteins are made?
2-3 binds and this allows 4 to be free and translate for more Trp.
What is quorum sensing?
Bacteria ability to sense cell density thus changing virulence factors to enhance resistance and survival.
