Respiration in Plants Question 52
52. Terminal cytochrome of respiratory chain
which donates electrons to oxygen is [1992]
(a) Cyt. b
(c) Cyt. $a_1$
(b) Cyt. $c$
(d) Cyt. $a_3$
Show Answer
Answer : d
Hints & Solutions
(d) Terminal cytochorome is cyt $a_3$. It posseses two copper centres. It helps in transfer of electrons to oxygen. 2 CuA molecules functions in allowing the electrons to enter the enzyme from cytochrome c. Heme $ _{a}$ functions in allowing the electrons to be transferred from CuA to the second heme, hemea3. The iron in heme $ _{a 3}$ functions in binding oxygen, with the help of $CuB$.
