FUCK you chris brown

Question 1

gene expression regulation

Answer 1

regulation of a functional gene product production at any level

Question 2

CRISPR-Cas

Answer 2

Clustered regularly interspaced short palindromic repeats
- an adaptive immune system

Question 3

sigma factor

Answer 3

a subunit of the prokaryotic RNA polymerase holoenzyme.
- recognises the promoter and is released after transcriptional initiation

Question 4

operator

Answer 4

a DNA sequence near the TSS to which a repressor protein binds

Question 5

Operon

Answer 5

a set of co-transcribed genes under the control of a single regulated promoter
- usually related functions

Question 6

attenuation

Answer 6

regulated premature termination of transcription

Question 7

attenuator

Answer 7

an RNA sequence that regulates expression by conditionally terminating transcription

Question 8

Pfam Family

Answer 8

protein sequences that are related to

Question 9

Pfam domain

Answer 9

autonomous structural unit or reusable sequence unit that can be found in multiple protein contexts

Question 10

E. coli genome

Answer 10

• 5Mb
• 4300 genes

Question 11

e. coli expression range

Answer 11

typical : ~3000 different proteins
High levels: ribosomal proteins 10,000/cell
low levels: regulators of transcription <10/cell

Question 12

inducible genes

Answer 12

• expression induced or repressed
• highly regulated

Question 13

house-keeping/constitutive genes

Answer 13

• not highly regulated
• constitutive always expressed

Question 14

why regulate gene expression

Answer 14

• conserve resources
• respond to environment
• ordered development

Question 15

coupled transcription and translation

Answer 15

• possible in prokaryotes as they lack a nucleus
• similar speeds
• help with translation as mRNA are rapidly degraded (avg. 1/2 life 2-3 mins)

Question 16

stages of CRISPR-Cas

Answer 16

• immunisation process (adaptation)
• interference process

Question 17

CRISPR immunisation process

Answer 17

• insertion of foreign DNA
• a complex of CRISPR associated Cas proteins (expressed from cas operon) recognises foreign DNA and cleaves a piece out
• DNA piece inserted into CRISPR ncRNA gene

Question 18

CRISPR interference

Answer 18

• CRISPR ncRNA is transcribed and processed into its final crRNA form
• combines with Cas proteins and are used as a guide to cleave corresponding nucleic acids

Question 19

Xpert MTB/RIF

Answer 19

tests for diseases using real-time RT-qPCR

Question 20

specific promoter regions

Answer 20

(-10), (-35)
- binding regions
- show some consensus between prokaryotes
- better match to consensus sequence = stronger promoter

+1 initiation site
- usually a purine

Question 21

sigma factors

Answer 21

• recognise promoters on the alpha helices
• six alt types
  
  • produced in different states ( heat or stress etc)
  • recognise different promoters and change gene expression in response to stimuli

Question 22

RNA polymerases

Answer 22

• DNA dependant
• 4+ subunits in the core
  - sigma
  - beta
  - alpha
• different from DNA pol
• Antibiotic target

Question 23

RNAP Beta subunits

Answer 23

• catalytic subunits

Question 25

Rho independent termination

Answer 25

- most common - specific hairpin or stem-loop structure - run of U in RNA - intrinsic terminator

Question 26

Rho dependant termination

Answer 26

- Rho binds to RNA and stops transcription

Question 27

Regulation of transcription

Answer 27

- promoter strength - presence of alternative sigma factors - presence of transcription factors

Question 28

trp operon

Answer 28

- biosynthetic operon - order of genes is the same as the pathway - enzymes are not made if tryptophan is already available