Final answer:
Cyanide poisoning through inhalation, especially in confined spaces, disrupts the electron transport chain by inhibiting cytochrome c oxidase, causing an increase in pH levels in the intermembrane space and halting ATP synthesis. Persistent profound metabolic acidosis is a true sign of cyanide toxicity.
Step-by-step explanation:
Cyanide Poisoning and Inhalation in Confined Spaces
Cyanide poisoning occurs due to exposure to various forms of cyanide, with inhalation being a critical route of exposure, particularly in confined spaces. When inhaled, cyanide binds to cytochrome c oxidase, which is a crucial component of the electron transport chain in cellular respiration. This binding leads to histotoxic hypoxia, meaning the body's tissues can no longer effectively use oxygen.
As for the pH of the intermembrane space, if cyanide poisoning occurs, we would expect it to increase. This is because the inhibition of cytochrome c oxidase disrupts the proton gradient, thereby reducing the flow of protons back into the mitochondrial matrix, which increases the pH in the intermembrane space. Additionally, this disruption halts ATP synthesis because the proton motive force is essential for driving the enzymes that synthesize ATP.
Metabolic acidosis is a significant sign of potential toxicity in cyanide poisoning. This is explained by the inability of cells to use oxygen and produce ATP efficiently, leading to lactate buildup as cells switch to anaerobic metabolic pathways to compensate for the energy deficit. Therefore, the statement about persistent profound metabolic acidosis being a sign of potential cyanide toxicity is true.