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TLS Online TPP Program

#Question id: 24434

Which of the following is correct order of proton-driven rotation of the c ring

#Unit 1. Molecules and their Interaction Relevant to Biology
  1. Arg210 rotates, displacing H+ from Asp → Proton displaces Arg210 to adjacent c subunit → Proton enters half channel on P side → Displaced H+ exits on N side → c10 ring rotates, Arg210 returns to P-side half-channel.
  2. Displaced H+ exits on N side→ Proton displaces Arg210 to adjacent c subunit → Arg210 rotates, displacing H+ from Asp → Proton enters half channel on P side→ c10 ring rotates, Arg210 returns to P-side half-channel.
  3. Proton enters half channel on P side → Proton displaces Arg210 to adjacent c subunit → Arg210 rotates, displacing H+ from Asp → Displaced H+ exits on N side → c10 ring rotates, Arg210 returns to P-side half-channel.
  4. Proton enters half channel on P side → Proton displaces Arg210 to adjacent c subunit → c10 ring rotates, Arg210 returns to P-side half-channel.→ Displaced H+ exits on N side → Arg210 rotates, displacing H+ from Asp.
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TLS Online TPP Program

#Question id: 4680

#Unit 3. Fundamental Processes

A protein is a transcriptional activator,  which binds to a site upstream of a promoter called PRE and stimulates transcription of the cI (repressor) gene. This activator protein is
TLS Online TPP Program

#Question id: 4681

#Unit 3. Fundamental Processes

The promoters whose activities are controlled by products of the genes transcribed from PR and PL
TLS Online TPP Program

#Question id: 4682

#Unit 3. Fundamental Processes

what will happen, when repressor bound at OR1 and OR2,
TLS Online TPP Program

#Question id: 4683

#Unit 3. Fundamental Processes

A very unstable protein in E. coli; it is degraded by a specific protease called FtsH (HflB), encoded by the hfl gene.
TLS Online TPP Program

#Question id: 4684

#Unit 3. Fundamental Processes

The depicted region contains two genes (cI and cro) and three promoters (PR, PL, and PRM), these promoters are direct the transcription such as;

a) PR and PL are is a weak promoter and only directs efficient transcription when an activator is bound just upstream

b) PR and PL are strong, constitutive promoters, they bind RNA polymerase efficiently and direct transcription without     help from an activator

c) PRM, is a weak promoter and only directs efficient transcription when an activator is bound just upstream

d) PRM are strong, constitutive promoters, they bind RNA polymerase efficiently and direct transcription without help from an activator

Which of the following from the above combination is correct ?
TLS Online TPP Program

#Question id: 4685

#Unit 3. Fundamental Processes

Some given characteristics of repressor such as;

 I) λ-repressor and

II) cro-repressor

a) A repressor binds DNA as a dimer

b) A repressor work as both activator and repressor

c) Repressor is a single-domain protein

d) Repressor binds to operator sites cooperatively

e) Only represses transcription, like the Lac repressor

which of the following are correct match statements  of given repressor