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: 9008

#Unit 6. System Physiology – Plant

Form I is the only type of Rubisco that harbors small subunits, and it consists of eight large and eight small subunits [L8S8]: Four dimers of large subunits [L2]4 capped by four small subunits at the top and the bottom [S4]2 build the hexadecameric structure {[S4]•[L2]4•[S4] = L8S8}

TLS Online TPP Program

#Id: 9009

#Unit 6. System Physiology – Plant

The assembly chaperone (RbcX)2 help to fold RUBISCO

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: 9011

#Unit 6. System Physiology – Plant

Rubisco-activase is regulated by light via the ferredoxin–thioredoxin system.

TLS Online TPP Program

#Id: 9012

#Unit 6. System Physiology – Plant

Ribulose 1,5-bisphosphate are sugar phosphates (SugP) inhibits carbamoylation by binding tightly to the active site and locking the enzyme in the “closed” confirmation.

TLS Online TPP Program

#Id: 9013

#Unit 6. System Physiology – Plant

Rubisco is inhibited by the natural inhibitor 2‐carboxyarabinitol 1‐phosphate (CA1P), that is a structural analog of the six-carbon intermediate of the carboxylation reaction.