Brain cells cannot ferment, and therefore have to respire to utilize glucose. Cyanide (CN-) closely resembles molecular oxygen, and binds tightly to cytochrome C oxidase, the electron carrier that reduces O2 during respiration. Cyanide is deadly to brain cells because in its presence:

a. O2 builds up in the cell
b. ATP cannot be synthesized from ADP
c. ADP cannot be produced from ATP
d. NAD+ cannot be generated from NADH
e. two of these answers are correct

Option E) two of these answers are correct

1) ATP cannot be synthesized from ADP

2) NAD+ cannot be generated from NADH

Explanation:

Cyanide ions combine tightly to cytochrome oxidase leading to a cessation of transfer of electrons to oxygen coupled with the accumulation of electron carriers in their reduced state (NADH), and the generation of high energy phosphate (ATP) from ADP stops.

Thus, the effects of cyanide is as fundamental as deprivation of oxygen, and causes rapid damage to the brain.

Option B.

Explanation:

Cyanide  poisoning is histoxic hypoxia to the brain and restrict the cells not to be able to produce ATP by inhibiting Mitochondria enzyme cytochrome c oxidase which help to synthesized ATP from ADP. Mitochondria is energy producing organelle, cyanide inhibit the Mitochondria enzyme from synthesizing ATP, cells dies because of lack of ATP. It prevent body cells from using oxygen. It affects the brain and heart because they use oxygen alot.

Cyanide poisoning can result from fumes, tobacco smoke e.t.c.