Why is this extra control of two layers on trp operon needed?  The answer probably lies in the fact that repression of the trp operon is weak—much weaker.

TLS Online TPP Program

#Id: 10218

#Unit 6. System Physiology – Plant

KNOX transcription factors activate the cytokinin biosynthetic gene ISOPENTENYL TRANSFERASE7 -IPT7

TLS Online TPP Program

#Id: 9010

#Unit 6. System Physiology – Plant

Only three molecules of CO2 are fixed per second per molecule of rubisco at 250C.

TLS Online TPP Program

#Id: 2432

#Unit 3. Fundamental Processes

When the RNA polymerase reaches the termination site, rho first freezes the structure of the polymerase and then invades the exit channel to destabilize the enzyme, causing it to release the RNA.

TLS Online TPP Program

#Id: 8644

#Unit 2. Cellular Organization

Phosphorylation on multiple sites by G1 CDKs blocks Rb from associating with E2F and promotes its export out of the nucleus.

TLS Online TPP Program

#Id: 8435

#Unit 10. Ecological Principles

r-selected species

High rate of per capita population growth

poor  competitive ability

Grows quickly 

age early, 

devoting much energy to producing  large number of progeny 

Small in size, and individuals do not live long. 

Random matting