Question

13. Which enzyme in plant cells allows for cyanide insensitivity?

a. NADH dehydrogenase

b. Cytochrome C reductase

c. Cytochrome oxidase

d. Alternate oxidase

Answer 1

Question 13:

In plants like pea and spinach, mitochondria use an alternate pathway or route to transport electrons, in the case of cyanide insensitivity. Hence the correct option is d) Alternate oxidase.

a. NADH dehydrogenase- electrons will be transported to ubiquinone or NADH dehydrogenase present in the inner mitochondrial membrane that will eventually be transported to flavoprotein to the alternate oxidase, for energy production.

b. Cytochrome C reductase- the redox reactions of the electron transport chain takes place.

c. Cytochrome oxidase- cyanide is an inhibitor to cytochrome oxidase in the electron transport system, that inhibits the transport of electrons to oxygen.

d. Alternate oxidase- Alternative oxidase, also called AOX, is an enzyme involved in the alternate route of electron transport that occurs in mitochondria when cyanide blocks cytochrome oxidase.