Final answer:
Cyanogenic glycosides are the agents that can cause cyanide toxicity, as they can metabolize into hydrogen cyanide which inhibits cytochrome c oxidase in the electron transport chain, preventing cells from utilizing oxygen effectively.
Step-by-step explanation:
The agent that can cause cyanide toxicity is C) Cyanogenic glycosides. These compounds are found naturally in many seeds and plants and can release hydrogen cyanide when metabolized. Cyanide works by inhibiting an essential enzyme in the electron transport chain, known as cytochrome c oxidase. This inhibition leads to a form of histotoxic hypoxia as the cells in the body are unable to effectively utilize oxygen, which is critical for the production of ATP through oxidative phosphorylation. Unlike the other listed options, cyanogenic glycosides are directly related to cyanide and its toxic effects.
Exposure to cyanide can come from a variety of sources such as smoke inhalation from house fires, which also often contains carbon monoxide that has a similar toxic effect by also binding to cytochrome c oxidase. Other potential exposure risks include occupations involving metal polishing, the use of certain insecticides, and consumption of foods containing higher levels of naturally occurring cyanogenic glycosides, like cassava or certain seeds and nuts.
While vitamin B12 in the form of hydroxocobalamin may help counteract chronic cyanide exposure, an acute poisoning scenario would result in symptoms such as headaches, dizziness, fast heart rate, shortness of breath, and potentially leading to seizures and metabolic acidosis due to the cells resorting to anaerobic respiration and the production of lactic acid. Immediate medical intervention would be crucial in the case of cyanide poisoning to mitigate the toxic effects and restore oxygen utilization at the cellular level.