Lecture 6 Bacterial Genome Replicaiton, Expression, And Reguluation 2 Mecahnisms Of Geneitc Variation Flashcards Preview

Microbiology > Lecture 6 Bacterial Genome Replicaiton, Expression, And Reguluation 2 Mecahnisms Of Geneitc Variation > Flashcards

Flashcards in Lecture 6 Bacterial Genome Replicaiton, Expression, And Reguluation 2 Mecahnisms Of Geneitc Variation Deck (14):
1

Methyl-accepting chemotaxis proteins (MCPs) are chemoreceptors in ______. That binds environmental chemicals and initiates a series of interactions with cytoplasmic proteins that affects _____

Membrane, flagella the rotation

2

Explain how methyl-accepting chemotaxis proteins (MCPs) can affect flagella the rotation

- Activates sensory kinase CheA (wiht help of CheW) which autophosphorylates
- CheA phosphorylase so the response regulator CheY
- CheY governs rotation of flagella

3

When attractant concentration is high MCP is ______. Thus leading to

Methylated (CheR) Thus leading to CheA/CheW is active (phosphorylated) thus phony lasting CheY wich leads to a clockwise (CW) rotation and a thumbless

4

When the attractant concentration decreases MCP is _______ thus

Not methylated (CHeB) thus CheA is inactive (not phosorylated) this means CheY is inactive and the flagellar rotation is counter-clockwise (CCW) and a run occurs

5

What is Quorum sensing

- Cell-to-cell communication mediated by small signaling a molecules such as N-acylhomoserine lactone (AHL)
- couples cells density and intercellular communication to transcription regulation

6

Example of Quorum sensing in V. Fischeri

- High concentrations of AHL produced by increased density of cells diffuse back into the cell, bind to the transcriptional regulator LuxR and active transcription
- LuxR stimulates transcription of the genes for AHL synthase (luxl) and proteins needed for light production

7

Sporulation is another example of global regulatory system in which ______, _______ , ______ and ______

- Phosphorelay, post translational modification of proteins, transcription initiation regulatory proteins and alternative sigma factors play a role.

8

Starvation signal induces production of _______ to lead to sporulation

Alternative sigma factors

9

Explain how starvation leads to alternative sigma factors

Kin A and Kin B phosphorylate Spo0F, which thus makes Spo0F-Phosphate, this phosphorylated Spo0B to make Spo0B-P this phosphorylated Spo0A to make Spo0A to make Spo0A-P which activate sigma f
- Sigma F leads to early sporulation of gene transcription and activates Active sigma G which leads to late sporulation gene transcription

10

Most prevalent form of a gene is called the

Wild type

11

What is a forward mutation

Wild type to mutant form

12

What is a reversion mutation

Mutant phenotype to wild type phenotype

13

What is a suppressor mutation

- A type of reversion mutation ( mutant phenotype to wild type phenotype) that occurs when the second mutation is at a different site than the original mutation but the wild type phenotype is still the same

14

An example of of post translational regulation is control of chemotaxis. Regulatory enzymes control chemotaxis proteins by _____ and ____

- Phosphorelay system
- Covalent modification