AP BIOLOGY

Detailed explanation-1: -The toxicity of cyanide is linked mainly to the cessation of aerobic cell metabolism. Cyanide reversibly binds to the ferric ions cytochrome oxidase three within the mitochondria. This effectively halts cellular respiration by blocking the reduction of oxygen to water.

Detailed explanation-2: -Cyanide binds to Fe3+ in heme-containing proteins. This inhibits the terminal cytochrome complex IV of the electron transport chain. The blocklock of complex IV by cyanide depletes ATP culminating in cell death. Oxygen is unable to reoxidize the reduced cytochrome a3.

Detailed explanation-3: -Cyanide inhibits cytochrome c oxidase, the terminal oxidase of the mitochondrial respiratory pathway, therefore inhibiting the cell oxygen utilization and resulting in the condition of histotoxic anoxia.

Detailed explanation-4: -Cyanide is a gas that inhibits complex IV of the electron transport chain. Cyanide combines with cytochrome oxidase and prevents the transfer of electrons to oxygen. Antimycin is a fungal antibiotic that inhibits complex III of the electron transport chain.

Detailed explanation-5: -In mammalian cells, cyanide is viewed as a cytotoxic agent, which exerts its effects through inhibition of mitochondrial Complex IV (Cytochrome C oxidase [CCOx]).