ATP synthase- CH 21

ATP synthase

assembly in inner mitochondrial membrane that carries out ATP synthesis 

synthesis of ATP

endergonic, powered by proton gradient

chemiosmotic hypothesis

main source to help produce ATP; complex enzyme w/ 2 large subunits

F1 subunit

contains catalytic activity; active site resides on b-subunits

the transfer of electrons through respiratory chain leads to

the pumping of protons from the matric to the cytoplasmic side of the inner mito. membrane; protons flow BACK into matrix to equalize distribution

Fo subunit

hydrophobic segment that contains proton channel of complex

c rings consists of multiple subunits that spin as a UNIT, those are

gamma + epsilon subunit

gamma subunit

turns to connect beta and conforms beta’s shape into 3 diff conformation states

ATP is produced in?

the beta subunits

1 of 3 possible active sites 

trapping of ADP + Pi

2 of 3 possible active sites

ATP synthesis

3 of 3 poss. active sites

ATP release and ADP + Pi binding

formation of cristae allows

proton pumps of ETC to localize the proton gradient in the vicinity of the synthases; cristae enhances efficiency of ATP synthesis

ATP synthase catalyzes the formation of:

ATP from ADP + orthophosphate

the enzyme consists of 

a moving unit or rotor consisting of c ring and ye stalk AND a stationary unit or stator composed of the remainder of the molecule 

second subunit

2nd: T or tight conformation; binds ATP w/ great affinity→ converts bound ADP + Pi into ATP

final subunit

O or open conformation; bind and release adenine

what are the 2 shuttles that carry electrons across inner membrane matrix

glycerol 3-phosphate and malate-aspartate shuttle

G3P shuttle

shuttles cytoplasmic NADH into ETC and the resulting FADH2 donates electrons to Q POOL

MA shuttle 

in the heart & liver, electrons from cytoplasmic NADH are brought into mitochondria; mediated by 2 membrane carriers + 4 enzymes 

ATP-ADP translocase

gets ADP + Pi INTO matrix and ATP OUT

adenine nucleotide transporter (ANT)

enables ATP and ADP to traverse the inner membrane; ADP enters only if ATP exits and vice versa