Noncoding RNAs, especially microRNAs, play a critical role in tumorigenesis:

Let-7 miRNAs

miR-15-a 

miR-16-1

miR-21

TLS Online TPP Program

#Id: 3296

#Unit 6. System Physiology – Plant

formation of ROS in two condition;
a) Mitochondria are not making ATP (for lack of ADP or O2) and therefore have a large proton-motive force and a high ratio of QH2/Q
b) there is a high NADH/NADratio in the matrix

TLS Online TPP Program

#Id: 3298

#Unit 6. System Physiology – Plant

TLS Online TPP Program

#Id: 3300

#Unit 6. System Physiology – Plant

Mitochondria is an respirosome, so it can avail oxygen out of complex IV and the oxygen used in the ETS without complex IV, always get converted into ROS.

TLS Online TPP Program

#Id: 3302

#Unit 6. System Physiology – Plant

In actively respiring mitochondria, 0.1% to as much as 4% of the O2 used in respiration forms •O2^2- — more than enough to have lethal effects unless the free radical is quickly disposed of.

TLS Online TPP Program

#Id: 3304

#Unit 6. System Physiology – Plant

Factors that slow the flow of electrons through the respiratory chain increase the formation of superoxide, perhaps by prolonging the lifetime of ^• O ₂ ^- generated in the Q cycle,

TLS Online TPP Program

#Id: 3305

#Unit 6. System Physiology – Plant

To prevent oxidative damage by • O2 2 , cells have several forms of the enzyme superoxide dismutase, which catalyzes the formation of hydrogen peroxide (H2O2)