Trp operon is negatively regulated by two ways

1. Repression

2. Attenuation

Why is this extra control of two layers on trp operon needed? 

TLS Online TPP Program

#Id: 3429

#Unit 6. System Physiology – Plant

In molecules, two types of excited states can exist;
a) The singlet state is relatively short‐lived and contains electrons with opposite (antiparallel) spins.
b) The more long‐lived triplet state has electron spins that are aligned (parallel).

TLS Online TPP Program

#Id: 3430

#Unit 6. System Physiology – Plant

Triplet states generally have much longer lives (take longer to de‐excite) than singlet states and are at a lower energy level.

TLS Online TPP Program

#Id: 3431

#Unit 6. System Physiology – Plant

Absorption of blue or red light causes the chlorophyll molecule to convert into an excited state, with blue light absorption resulting in a higher excited state because of the greater energy of blue light relative to red light.

TLS Online TPP Program

#Id: 3449

#Unit 6. System Physiology – Plant

DCMU, an inhibitor of PSII

DBMIB, an inhibitor of the Cyt b6 f complex

Paraquat (methyl viologen), an inhibitor of PSI

TLS Online TPP Program

#Id: 3541

#Unit 6. System Physiology – Plant

Three phases of the Calvin–Benson cycle: carboxylation, reduction, and regeneration

TLS Online TPP Program

#Id: 3562

#Unit 6. System Physiology – Plant

Carbon–carbon bond between C2 and C3 of the RuBP is cleaved for CO2 fixation.