Question
Which ofthe following is true regarding the given electron transport chain?
CoQ Cyt c Cyt aa3 O2
CoQ Cyt c is H+ absorbing site
aa3 O2, H+ yielding site
CoQ Cyt c is H+ yielding site and aa3 O2 is H+ absorbing site
No H+ is absorbed or released
Solution
C.
CoQ Cyt c is H+ yielding site and aa3 O2 is H+ absorbing site
In electron transport chain electrons transport through a series of carriers. H+ of NADH+ (received from Kreb' s cycle) is accepted by FAD as a result of which FAD is reduced to FADH+ and NADH+ is oxidised to NAD. Reduced FADH+ is oxidised by CoQ with the formation of CoQH+. H+ ions then move to Cyt b, then Cyt c, Cyt a and Cyt aa3. Ultimately these H+ are acceped by O2 and H2O is formed.
